update existing metadata to 1.17, using new system

src/main/java/net/minestom/server/entity/Metadata.java

@@ -238,20 +238,20 @@ public class Metadata {
     }
 
     @SuppressWarnings("unchecked")
-    public <T> T getIndex(byte index, @Nullable T defaultValue) {
+    public <T> T getIndex(int index, @Nullable T defaultValue) {
-        Entry<?> value = this.metadataMap.get(index);
+        Entry<?> value = this.metadataMap.get((byte) index);
         return value != null ? (T) value.getMetaValue().value : defaultValue;
     }
 
-    public void setIndex(byte index, @NotNull Value<?> value) {
+    public void setIndex(int index, @NotNull Value<?> value) {
-        final Entry<?> entry = new Entry<>(index, value);
+        final Entry<?> entry = new Entry<>((byte) index, value);
-        this.metadataMap.put(index, entry);
+        this.metadataMap.put((byte) index, entry);
 
         // Send metadata packet to update viewers and self
         if (this.entity != null && this.entity.isActive()) {
             if (!this.notifyAboutChanges) {
                 synchronized (this.notNotifiedChanges) {
-                    this.notNotifiedChanges.put(index, entry);
+                    this.notNotifiedChanges.put((byte) index, entry);
                 }
                 return;
             }

src/main/java/net/minestom/server/entity/metadata/AgeableMobMeta.java

@@ -6,13 +6,15 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class AgeableMobMeta extends PathfinderMobMeta {
+    public static final byte OFFSET = PathfinderMobMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     protected AgeableMobMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
     }
 
     public boolean isBaby() {
-        return super.metadata.getIndex((byte) 15, false);
+        return super.metadata.getIndex(OFFSET, false);
     }
 
     public void setBaby(boolean value) {
@@ -25,7 +27,7 @@ public class AgeableMobMeta extends PathfinderMobMeta {
         } else {
             setBoundingBox(bb.getWidth() * 2, bb.getHeight() * 2);
         }
-        super.metadata.setIndex((byte) 15, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET, Metadata.Boolean(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/EntityMeta.java

@@ -7,8 +7,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class EntityMeta {
-
+    public static final byte OFFSET = 0;
-    private final static byte MASK_INDEX = 0;
+    public static final byte MAX_OFFSET = OFFSET + 8;
 
     private final static byte ON_FIRE_BIT = 0x01;
     private final static byte CROUNCHING_BIT = 0x02;
@@ -44,67 +44,67 @@ public class EntityMeta {
     }
 
     public boolean isOnFire() {
-        return getMaskBit(MASK_INDEX, ON_FIRE_BIT);
+        return getMaskBit(OFFSET, ON_FIRE_BIT);
     }
 
     public void setOnFire(boolean value) {
-        setMaskBit(MASK_INDEX, ON_FIRE_BIT, value);
+        setMaskBit(OFFSET, ON_FIRE_BIT, value);
     }
 
     public boolean isSneaking() {
-        return getMaskBit(MASK_INDEX, CROUNCHING_BIT);
+        return getMaskBit(OFFSET, CROUNCHING_BIT);
     }
 
     public void setSneaking(boolean value) {
-        setMaskBit(MASK_INDEX, CROUNCHING_BIT, value);
+        setMaskBit(OFFSET, CROUNCHING_BIT, value);
     }
 
     public boolean isSprinting() {
-        return getMaskBit(MASK_INDEX, SPRINTING_BIT);
+        return getMaskBit(OFFSET, SPRINTING_BIT);
     }
 
     public void setSprinting(boolean value) {
-        setMaskBit(MASK_INDEX, SPRINTING_BIT, value);
+        setMaskBit(OFFSET, SPRINTING_BIT, value);
     }
 
     public boolean isSwimming() {
-        return getMaskBit(MASK_INDEX, SWIMMING_BIT);
+        return getMaskBit(OFFSET, SWIMMING_BIT);
     }
 
     public void setSwimming(boolean value) {
-        setMaskBit(MASK_INDEX, SWIMMING_BIT, value);
+        setMaskBit(OFFSET, SWIMMING_BIT, value);
     }
 
     public boolean isInvisible() {
-        return getMaskBit(MASK_INDEX, INVISIBLE_BIT);
+        return getMaskBit(OFFSET, INVISIBLE_BIT);
     }
 
     public void setInvisible(boolean value) {
-        setMaskBit(MASK_INDEX, INVISIBLE_BIT, value);
+        setMaskBit(OFFSET, INVISIBLE_BIT, value);
     }
 
     public boolean isHasGlowingEffect() {
-        return getMaskBit(MASK_INDEX, HAS_GLOWING_EFFECT_BIT);
+        return getMaskBit(OFFSET, HAS_GLOWING_EFFECT_BIT);
     }
 
     public void setHasGlowingEffect(boolean value) {
-        setMaskBit(MASK_INDEX, HAS_GLOWING_EFFECT_BIT, value);
+        setMaskBit(OFFSET, HAS_GLOWING_EFFECT_BIT, value);
     }
 
     public boolean isFlyingWithElytra() {
-        return getMaskBit(MASK_INDEX, FLYING_WITH_ELYTRA_BIT);
+        return getMaskBit(OFFSET, FLYING_WITH_ELYTRA_BIT);
     }
 
     public void setFlyingWithElytra(boolean value) {
-        setMaskBit(MASK_INDEX, FLYING_WITH_ELYTRA_BIT, value);
+        setMaskBit(OFFSET, FLYING_WITH_ELYTRA_BIT, value);
     }
 
     public int getAirTicks() {
-        return this.metadata.getIndex((byte) 1, 300);
+        return this.metadata.getIndex(OFFSET + 1, 300);
     }
 
     public void setAirTicks(int value) {
-        this.metadata.setIndex((byte) 1, Metadata.VarInt(value));
+        this.metadata.setIndex(OFFSET + 1, Metadata.VarInt(value));
     }
 
     /**
@@ -126,66 +126,66 @@ public class EntityMeta {
     }
 
     public Component getCustomName() {
-        return this.metadata.getIndex((byte) 2, null);
+        return this.metadata.getIndex(OFFSET + 2, null);
     }
 
     public void setCustomName(Component value) {
-        this.metadata.setIndex((byte) 2, Metadata.OptChat(value));
+        this.metadata.setIndex(OFFSET + 2, Metadata.OptChat(value));
     }
 
     public boolean isCustomNameVisible() {
-        return this.metadata.getIndex((byte) 3, false);
+        return this.metadata.getIndex(OFFSET + 3, false);
     }
 
     public void setCustomNameVisible(boolean value) {
-        this.metadata.setIndex((byte) 3, Metadata.Boolean(value));
+        this.metadata.setIndex(OFFSET + 3, Metadata.Boolean(value));
     }
 
     public boolean isSilent() {
-        return this.metadata.getIndex((byte) 4, false);
+        return this.metadata.getIndex(OFFSET + 4, false);
     }
 
     public void setSilent(boolean value) {
-        this.metadata.setIndex((byte) 4, Metadata.Boolean(value));
+        this.metadata.setIndex(OFFSET + 4, Metadata.Boolean(value));
     }
 
     public boolean isHasNoGravity() {
-        return this.metadata.getIndex((byte) 5, false);
+        return this.metadata.getIndex(OFFSET + 5, false);
     }
 
     public void setHasNoGravity(boolean value) {
-        this.metadata.setIndex((byte) 5, Metadata.Boolean(value));
+        this.metadata.setIndex(OFFSET + 5, Metadata.Boolean(value));
     }
 
     public Entity.Pose getPose() {
-        return this.metadata.getIndex((byte) 6, Entity.Pose.STANDING);
+        return this.metadata.getIndex(OFFSET + 6, Entity.Pose.STANDING);
     }
 
     public void setPose(Entity.Pose value) {
-        this.metadata.setIndex((byte) 6, Metadata.Pose(value));
+        this.metadata.setIndex(OFFSET + 6, Metadata.Pose(value));
     }
 
     public int getTickFrozen() {
-        return this.metadata.getIndex((byte) 7, 0);
+        return this.metadata.getIndex(OFFSET + 7, 0);
     }
 
     public void setTickFrozen(int tickFrozen) {
-        this.metadata.setIndex((byte) 7, Metadata.VarInt(tickFrozen));
+        this.metadata.setIndex(OFFSET + 7, Metadata.VarInt(tickFrozen));
     }
 
-    protected byte getMask(byte index) {
+    protected byte getMask(int index) {
         return this.metadata.getIndex(index, (byte) 0);
     }
 
-    protected void setMask(byte index, byte mask) {
+    protected void setMask(int index, byte mask) {
         this.metadata.setIndex(index, Metadata.Byte(mask));
     }
 
-    protected boolean getMaskBit(byte index, byte bit) {
+    protected boolean getMaskBit(int index, byte bit) {
         return (getMask(index) & bit) == bit;
     }
 
-    protected void setMaskBit(byte index, byte bit, boolean value) {
+    protected void setMaskBit(int index, byte bit, boolean value) {
         byte mask = getMask(index);
         boolean currentValue = (mask & bit) == bit;
         if (currentValue == value) {

src/main/java/net/minestom/server/entity/metadata/LivingEntityMeta.java

@@ -8,8 +8,8 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 public class LivingEntityMeta extends EntityMeta {
-
+    public static final byte OFFSET = EntityMeta.MAX_OFFSET;
-    private final static byte MASK_INDEX = 7;
+    public static final byte MAX_OFFSET = OFFSET + 7;
 
     private final static byte IS_HAND_ACTIVE_BIT = 0x01;
     private final static byte ACTIVE_HAND_BIT = 0x02;
@@ -20,77 +20,77 @@ public class LivingEntityMeta extends EntityMeta {
     }
 
     public boolean isHandActive() {
-        return getMaskBit(MASK_INDEX, IS_HAND_ACTIVE_BIT);
+        return getMaskBit(OFFSET, IS_HAND_ACTIVE_BIT);
     }
 
     public void setHandActive(boolean value) {
-        setMaskBit(MASK_INDEX, IS_HAND_ACTIVE_BIT, value);
+        setMaskBit(OFFSET, IS_HAND_ACTIVE_BIT, value);
     }
 
     @NotNull
     public Player.Hand getActiveHand() {
-        return getMaskBit(MASK_INDEX, ACTIVE_HAND_BIT) ? Player.Hand.OFF : Player.Hand.MAIN;
+        return getMaskBit(OFFSET, ACTIVE_HAND_BIT) ? Player.Hand.OFF : Player.Hand.MAIN;
     }
 
     public void setActiveHand(@NotNull Player.Hand hand) {
-        setMaskBit(MASK_INDEX, ACTIVE_HAND_BIT, hand == Player.Hand.OFF);
+        setMaskBit(OFFSET, ACTIVE_HAND_BIT, hand == Player.Hand.OFF);
     }
 
     public boolean isInRiptideSpinAttack() {
-        return getMaskBit(MASK_INDEX, IS_IN_SPIN_ATTACK_BIT);
+        return getMaskBit(OFFSET, IS_IN_SPIN_ATTACK_BIT);
     }
 
     public void setInRiptideSpinAttack(boolean value) {
-        setMaskBit(MASK_INDEX, IS_IN_SPIN_ATTACK_BIT, value);
+        setMaskBit(OFFSET, IS_IN_SPIN_ATTACK_BIT, value);
     }
 
     public float getHealth() {
-        return super.metadata.getIndex((byte) 8, 1F);
+        return super.metadata.getIndex(OFFSET + 1, 1F);
     }
 
     public void setHealth(float value) {
-        super.metadata.setIndex((byte) 8, Metadata.Float(value));
+        super.metadata.setIndex(OFFSET + 1, Metadata.Float(value));
     }
 
     public int getPotionEffectColor() {
-        return super.metadata.getIndex((byte) 9, 0);
+        return super.metadata.getIndex(OFFSET + 2, 0);
     }
 
     public void setPotionEffectColor(int value) {
-        super.metadata.setIndex((byte) 9, Metadata.VarInt(value));
+        super.metadata.setIndex(OFFSET + 2, Metadata.VarInt(value));
     }
 
     public boolean isPotionEffectAmbient() {
-        return super.metadata.getIndex((byte) 10, false);
+        return super.metadata.getIndex(OFFSET + 3, false);
     }
 
     public void setPotionEffectAmbient(boolean value) {
-        super.metadata.setIndex((byte) 10, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET + 3, Metadata.Boolean(value));
     }
 
     public int getArrowCount() {
-        return super.metadata.getIndex((byte) 11, 0);
+        return super.metadata.getIndex(OFFSET + 4, 0);
     }
 
     public void setArrowCount(int value) {
-        super.metadata.getIndex((byte) 11, Metadata.VarInt(value));
+        super.metadata.getIndex(OFFSET + 4, Metadata.VarInt(value));
     }
 
     public int getHealthAddedByAbsorption() {
-        return super.metadata.getIndex((byte) 12, 0);
+        return super.metadata.getIndex(OFFSET + 5, 0);
     }
 
     public void setHealthAddedByAbsorption(int value) {
-        super.metadata.getIndex((byte) 12, Metadata.VarInt(value));
+        super.metadata.getIndex(OFFSET + 5, Metadata.VarInt(value));
     }
 
     @Nullable
     public BlockPosition getBedInWhichSleepingPosition() {
-        return super.metadata.getIndex((byte) 13, null);
+        return super.metadata.getIndex(OFFSET + 6, null);
     }
 
     public void setBedInWhichSleepingPosition(@Nullable BlockPosition value) {
-        super.metadata.setIndex((byte) 13, Metadata.OptPosition(value));
+        super.metadata.setIndex(OFFSET + 6, Metadata.OptPosition(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/MobMeta.java

@@ -5,8 +5,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class MobMeta extends LivingEntityMeta {
-
+    public static final byte OFFSET = LivingEntityMeta.MAX_OFFSET;
-    private final static byte MASK_INDEX = 14;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     private final static byte NO_AI_BIT = 0x01;
     private final static byte IS_LEFT_HANDED_BIT = 0x02;
@@ -17,27 +17,27 @@ public class MobMeta extends LivingEntityMeta {
     }
 
     public boolean isNoAi() {
-        return getMaskBit(MASK_INDEX, NO_AI_BIT);
+        return getMaskBit(OFFSET, NO_AI_BIT);
     }
 
     public void setNoAi(boolean value) {
-        setMaskBit(MASK_INDEX, NO_AI_BIT, value);
+        setMaskBit(OFFSET, NO_AI_BIT, value);
     }
 
     public boolean isLeftHanded() {
-        return getMaskBit(MASK_INDEX, IS_LEFT_HANDED_BIT);
+        return getMaskBit(OFFSET, IS_LEFT_HANDED_BIT);
     }
 
     public void setLeftHanded(boolean value) {
-        setMaskBit(MASK_INDEX, IS_LEFT_HANDED_BIT, value);
+        setMaskBit(OFFSET, IS_LEFT_HANDED_BIT, value);
     }
 
     public boolean isAggressive() {
-        return getMaskBit(MASK_INDEX, IS_AGGRESSIVE_BIT);
+        return getMaskBit(OFFSET, IS_AGGRESSIVE_BIT);
     }
 
     public void setAggressive(boolean value) {
-        setMaskBit(MASK_INDEX, IS_AGGRESSIVE_BIT, value);
+        setMaskBit(OFFSET, IS_AGGRESSIVE_BIT, value);
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/PathfinderMobMeta.java

@@ -5,6 +5,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class PathfinderMobMeta extends MobMeta {
+    public static final byte OFFSET = MobMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     protected PathfinderMobMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/PlayerMeta.java

@@ -7,8 +7,8 @@ import org.jetbrains.annotations.Nullable;
 import org.jglrxavpok.hephaistos.nbt.NBT;
 
 public class PlayerMeta extends LivingEntityMeta {
-
+    public static final byte OFFSET = LivingEntityMeta.MAX_OFFSET;
-    private final static byte MASK_INDEX = 16;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     private final static byte CAPE_BIT = 0x01;
     private final static byte JACKET_BIT = 0x02;
@@ -23,101 +23,101 @@ public class PlayerMeta extends LivingEntityMeta {
     }
 
     public float getAdditionalHearts() {
-        return super.metadata.getIndex((byte) 14, 0F);
+        return super.metadata.getIndex(OFFSET, 0F);
     }
 
     public void setAdditionalHearts(float value) {
-        super.metadata.setIndex((byte) 14, Metadata.Float(value));
+        super.metadata.setIndex(OFFSET, Metadata.Float(value));
     }
 
     public int getScore() {
-        return super.metadata.getIndex((byte) 15, 0);
+        return super.metadata.getIndex(OFFSET + 1, 0);
     }
 
     public void setScore(int value) {
-        super.metadata.setIndex((byte) 15, Metadata.VarInt(value));
+        super.metadata.setIndex(OFFSET + 1, Metadata.VarInt(value));
     }
 
     public boolean isCapeEnabled() {
-        return getMaskBit(MASK_INDEX, CAPE_BIT);
+        return getMaskBit(OFFSET + 2, CAPE_BIT);
     }
 
     public void setCapeEnabled(boolean value) {
-        setMaskBit(MASK_INDEX, CAPE_BIT, value);
+        setMaskBit(OFFSET + 2, CAPE_BIT, value);
     }
 
     public boolean isJacketEnabled() {
-        return getMaskBit(MASK_INDEX, JACKET_BIT);
+        return getMaskBit(OFFSET + 2, JACKET_BIT);
     }
 
     public void setJacketEnabled(boolean value) {
-        setMaskBit(MASK_INDEX, JACKET_BIT, value);
+        setMaskBit(OFFSET + 2, JACKET_BIT, value);
     }
 
     public boolean isLeftSleeveEnabled() {
-        return getMaskBit(MASK_INDEX, LEFT_SLEEVE_BIT);
+        return getMaskBit(OFFSET + 2, LEFT_SLEEVE_BIT);
     }
 
     public void setLeftSleeveEnabled(boolean value) {
-        setMaskBit(MASK_INDEX, LEFT_SLEEVE_BIT, value);
+        setMaskBit(OFFSET + 2, LEFT_SLEEVE_BIT, value);
     }
 
     public boolean isRightSleeveEnabled() {
-        return getMaskBit(MASK_INDEX, RIGHT_SLEEVE_BIT);
+        return getMaskBit(OFFSET + 2, RIGHT_SLEEVE_BIT);
     }
 
     public void setRightSleeveEnabled(boolean value) {
-        setMaskBit(MASK_INDEX, RIGHT_SLEEVE_BIT, value);
+        setMaskBit(OFFSET + 2, RIGHT_SLEEVE_BIT, value);
     }
 
     public boolean isLeftLegEnabled() {
-        return getMaskBit(MASK_INDEX, LEFT_LEG_BIT);
+        return getMaskBit(OFFSET + 2, LEFT_LEG_BIT);
     }
 
     public void setLeftLegEnabled(boolean value) {
-        setMaskBit(MASK_INDEX, LEFT_LEG_BIT, value);
+        setMaskBit(OFFSET + 2, LEFT_LEG_BIT, value);
     }
 
     public boolean isRightLegEnabled() {
-        return getMaskBit(MASK_INDEX, RIGHT_LEG_BIT);
+        return getMaskBit(OFFSET + 2, RIGHT_LEG_BIT);
     }
 
     public void setRightLegEnabled(boolean value) {
-        setMaskBit(MASK_INDEX, RIGHT_LEG_BIT, value);
+        setMaskBit(OFFSET + 2, RIGHT_LEG_BIT, value);
     }
 
     public boolean isHatEnabled() {
-        return getMaskBit(MASK_INDEX, HAT_BIT);
+        return getMaskBit(OFFSET + 2, HAT_BIT);
     }
 
     public void setHatEnabled(boolean value) {
-        setMaskBit(MASK_INDEX, HAT_BIT, value);
+        setMaskBit(OFFSET + 2, HAT_BIT, value);
     }
 
     public boolean isRightMainHand() {
-        return super.metadata.getIndex((byte) 17, (byte) 1) == (byte) 1;
+        return super.metadata.getIndex(OFFSET + 3, (byte) 1) == (byte) 1;
     }
 
     public void setRightMainHand(boolean value) {
-        super.metadata.setIndex((byte) 17, Metadata.Byte(value ? (byte) 1 : (byte) 0));
+        super.metadata.setIndex(OFFSET + 3, Metadata.Byte(value ? (byte) 1 : (byte) 0));
     }
 
     @Nullable
     public NBT getLeftShoulderEntityData() {
-        return super.metadata.getIndex((byte) 18, null);
+        return super.metadata.getIndex(OFFSET + 4, null);
     }
 
     public void setLeftShoulderEntityData(@Nullable NBT value) {
-        super.metadata.setIndex((byte) 18, Metadata.NBT(value));
+        super.metadata.setIndex(OFFSET + 4, Metadata.NBT(value));
     }
 
     @Nullable
     public NBT getRightShoulderEntityData() {
-        return super.metadata.getIndex((byte) 19, null);
+        return super.metadata.getIndex(OFFSET + 5, null);
     }
 
     public void setRightShoulderEntityData(@Nullable NBT value) {
-        super.metadata.setIndex((byte) 19, Metadata.NBT(value));
+        super.metadata.setIndex(OFFSET + 5, Metadata.NBT(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/ambient/AmbientCreatureMeta.java

@@ -2,10 +2,13 @@ package net.minestom.server.entity.metadata.ambient;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.LivingEntityMeta;
 import net.minestom.server.entity.metadata.MobMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class AmbientCreatureMeta extends MobMeta {
+    public static final byte OFFSET = MobMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     protected AmbientCreatureMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/ambient/BatMeta.java

@@ -2,11 +2,12 @@ package net.minestom.server.entity.metadata.ambient;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.LivingEntityMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class BatMeta extends AmbientCreatureMeta {
-
+    public static final byte OFFSET = AmbientCreatureMeta.MAX_OFFSET;
-    private final static byte MASK_INDEX = 15;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     private final static byte IS_HANGING_BIT = 0x01;
 
@@ -15,11 +16,11 @@ public class BatMeta extends AmbientCreatureMeta {
     }
 
     public boolean isHanging() {
-        return getMaskBit(MASK_INDEX, IS_HANGING_BIT);
+        return getMaskBit(OFFSET, IS_HANGING_BIT);
     }
 
     public void setHanging(boolean value) {
-        setMaskBit(MASK_INDEX, IS_HANGING_BIT, value);
+        setMaskBit(OFFSET, IS_HANGING_BIT, value);
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/animal/AbstractHorseMeta.java

@@ -2,13 +2,14 @@ package net.minestom.server.entity.metadata.animal;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.LivingEntityMeta;
 import org.jetbrains.annotations.NotNull;
 
 import java.util.UUID;
 
 public class AbstractHorseMeta extends AnimalMeta {
-
+    public static final byte OFFSET = AnimalMeta.MAX_OFFSET;
-    private final static byte MASK_INDEX = 16;
+    public static final byte MAX_OFFSET = OFFSET + 2;
 
     private final static byte TAMED_BIT = 0x02;
     private final static byte SADDLED_BIT = 0x04;
@@ -22,59 +23,59 @@ public class AbstractHorseMeta extends AnimalMeta {
     }
 
     public boolean isTamed() {
-        return getMaskBit(MASK_INDEX, TAMED_BIT);
+        return getMaskBit(OFFSET, TAMED_BIT);
     }
 
     public void setTamed(boolean value) {
-        setMaskBit(MASK_INDEX, TAMED_BIT, value);
+        setMaskBit(OFFSET, TAMED_BIT, value);
     }
 
     public boolean isSaddled() {
-        return getMaskBit(MASK_INDEX, SADDLED_BIT);
+        return getMaskBit(OFFSET, SADDLED_BIT);
     }
 
     public void setSaddled(boolean value) {
-        setMaskBit(MASK_INDEX, SADDLED_BIT, value);
+        setMaskBit(OFFSET, SADDLED_BIT, value);
     }
 
     public boolean isHasBred() {
-        return getMaskBit(MASK_INDEX, HAS_BRED_BIT);
+        return getMaskBit(OFFSET, HAS_BRED_BIT);
     }
 
     public void setHasBred(boolean value) {
-        setMaskBit(MASK_INDEX, HAS_BRED_BIT, value);
+        setMaskBit(OFFSET, HAS_BRED_BIT, value);
     }
 
     public boolean isEating() {
-        return getMaskBit(MASK_INDEX, EATING_BIT);
+        return getMaskBit(OFFSET, EATING_BIT);
     }
 
     public void setEating(boolean value) {
-        setMaskBit(MASK_INDEX, EATING_BIT, value);
+        setMaskBit(OFFSET, EATING_BIT, value);
     }
 
     public boolean isRearing() {
-        return getMaskBit(MASK_INDEX, REARING_BIT);
+        return getMaskBit(OFFSET, REARING_BIT);
     }
 
     public void setRearing(boolean value) {
-        setMaskBit(MASK_INDEX, REARING_BIT, value);
+        setMaskBit(OFFSET, REARING_BIT, value);
     }
 
     public boolean isMouthOpen() {
-        return getMaskBit(MASK_INDEX, MOUTH_OPEN_BIT);
+        return getMaskBit(OFFSET, MOUTH_OPEN_BIT);
     }
 
     public void setMouthOpen(boolean value) {
-        setMaskBit(MASK_INDEX, MOUTH_OPEN_BIT, value);
+        setMaskBit(OFFSET, MOUTH_OPEN_BIT, value);
     }
 
     public UUID getOwner() {
-        return super.metadata.getIndex((byte) 17, null);
+        return super.metadata.getIndex(OFFSET + 1, null);
     }
 
     public void setOwner(UUID value) {
-        super.metadata.setIndex((byte) 17, Metadata.OptUUID(value));
+        super.metadata.setIndex(OFFSET + 1, Metadata.OptUUID(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/animal/AnimalMeta.java

@@ -3,9 +3,12 @@ package net.minestom.server.entity.metadata.animal;
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
 import net.minestom.server.entity.metadata.AgeableMobMeta;
+import net.minestom.server.entity.metadata.LivingEntityMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class AnimalMeta extends AgeableMobMeta {
+    public static final byte OFFSET = AgeableMobMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     protected AnimalMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/animal/BeeMeta.java

@@ -2,11 +2,13 @@ package net.minestom.server.entity.metadata.animal;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.LivingEntityMeta;
+import net.minestom.server.entity.metadata.ambient.AmbientCreatureMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class BeeMeta extends AnimalMeta {
-
+    public static final byte OFFSET = AnimalMeta.MAX_OFFSET;
-    private final static byte MASK_INDEX = 16;
+    public static final byte MAX_OFFSET = OFFSET + 2;
 
     private final static byte ANGRY_BIT = 0x02;
     private final static byte HAS_STUNG_BIT = 0x04;
@@ -17,35 +19,35 @@ public class BeeMeta extends AnimalMeta {
     }
 
     public boolean isAngry() {
-        return getMaskBit(MASK_INDEX, ANGRY_BIT);
+        return getMaskBit(OFFSET, ANGRY_BIT);
     }
 
     public void setAngry(boolean value) {
-        setMaskBit(MASK_INDEX, ANGRY_BIT, value);
+        setMaskBit(OFFSET, ANGRY_BIT, value);
     }
 
     public boolean isHasStung() {
-        return getMaskBit(MASK_INDEX, HAS_STUNG_BIT);
+        return getMaskBit(OFFSET, HAS_STUNG_BIT);
     }
 
     public void setHasStung(boolean value) {
-        setMaskBit(MASK_INDEX, HAS_STUNG_BIT, value);
+        setMaskBit(OFFSET, HAS_STUNG_BIT, value);
     }
 
     public boolean isHasNectar() {
-        return getMaskBit(MASK_INDEX, HAS_NECTAR_BIT);
+        return getMaskBit(OFFSET, HAS_NECTAR_BIT);
     }
 
     public void setHasNectar(boolean value) {
-        setMaskBit(MASK_INDEX, HAS_NECTAR_BIT, value);
+        setMaskBit(OFFSET, HAS_NECTAR_BIT, value);
     }
 
     public int getAngerTicks() {
-        return super.metadata.getIndex((byte) 17, 0);
+        return super.metadata.getIndex(OFFSET + 1, 0);
     }
 
     public void setAngerTicks(int value) {
-        super.metadata.setIndex((byte) 17, Metadata.VarInt(value));
+        super.metadata.setIndex(OFFSET + 1, Metadata.VarInt(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/animal/ChestedHorseMeta.java

@@ -2,20 +2,23 @@ package net.minestom.server.entity.metadata.animal;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.LivingEntityMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class ChestedHorseMeta extends AbstractHorseMeta {
+    public static final byte OFFSET = AbstractHorseMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     protected ChestedHorseMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
     }
 
     public boolean isHasChest() {
-        return super.metadata.getIndex((byte) 18, false);
+        return super.metadata.getIndex(OFFSET, false);
     }
 
     public void setHasChest(boolean value) {
-        super.metadata.setIndex((byte) 18, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET, Metadata.Boolean(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/animal/ChickenMeta.java

@@ -2,9 +2,12 @@ package net.minestom.server.entity.metadata.animal;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.LivingEntityMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class ChickenMeta extends AnimalMeta {
+    public static final byte OFFSET = AnimalMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public ChickenMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/animal/CowMeta.java

@@ -2,9 +2,12 @@ package net.minestom.server.entity.metadata.animal;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.LivingEntityMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class CowMeta extends AnimalMeta {
+    public static final byte OFFSET = AnimalMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public CowMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/animal/DonkeyMeta.java

@@ -5,6 +5,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class DonkeyMeta extends ChestedHorseMeta {
+    public static final byte OFFSET = AnimalMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public DonkeyMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/animal/FoxMeta.java

@@ -8,8 +8,8 @@ import org.jetbrains.annotations.Nullable;
 import java.util.UUID;
 
 public class FoxMeta extends AnimalMeta {
-
+    public static final byte OFFSET = AnimalMeta.MAX_OFFSET;
-    private final static byte MASK_INDEX = 17;
+    public static final byte MAX_OFFSET = OFFSET + 4;
 
     private final static byte SITTING_BIT = 0x01;
     private final static byte CROUCHING_BIT = 0x04;
@@ -25,85 +25,85 @@ public class FoxMeta extends AnimalMeta {
 
     @NotNull
     public Type getType() {
-        return Type.VALUES[super.metadata.getIndex((byte) 16, 0)];
+        return Type.VALUES[super.metadata.getIndex(OFFSET, 0)];
     }
 
     public void setType(@NotNull Type type) {
-        super.metadata.setIndex((byte) 16, Metadata.VarInt(type.ordinal()));
+        super.metadata.setIndex(OFFSET, Metadata.VarInt(type.ordinal()));
     }
 
     public boolean isSitting() {
-        return getMaskBit(MASK_INDEX, SITTING_BIT);
+        return getMaskBit(OFFSET + 1, SITTING_BIT);
     }
 
     public void setSitting(boolean value) {
-        setMaskBit(MASK_INDEX, SITTING_BIT, value);
+        setMaskBit(OFFSET + 1, SITTING_BIT, value);
     }
 
     public boolean isFoxSneaking() {
-        return getMaskBit(MASK_INDEX, CROUCHING_BIT);
+        return getMaskBit(OFFSET + 1, CROUCHING_BIT);
     }
 
     public void setFoxSneaking(boolean value) {
-        setMaskBit(MASK_INDEX, CROUCHING_BIT, value);
+        setMaskBit(OFFSET + 1, CROUCHING_BIT, value);
     }
 
     public boolean isInterested() {
-        return getMaskBit(MASK_INDEX, INTERESTED_BIT);
+        return getMaskBit(OFFSET + 1, INTERESTED_BIT);
     }
 
     public void setInterested(boolean value) {
-        setMaskBit(MASK_INDEX, INTERESTED_BIT, value);
+        setMaskBit(OFFSET + 1, INTERESTED_BIT, value);
     }
 
     public boolean isPouncing() {
-        return getMaskBit(MASK_INDEX, POUNCING_BIT);
+        return getMaskBit(OFFSET + 1, POUNCING_BIT);
     }
 
     public void setPouncing(boolean value) {
-        setMaskBit(MASK_INDEX, POUNCING_BIT, value);
+        setMaskBit(OFFSET + 1, POUNCING_BIT, value);
     }
 
     public boolean isSleeping() {
-        return getMaskBit(MASK_INDEX, SLEEPING_BIT);
+        return getMaskBit(OFFSET + 1, SLEEPING_BIT);
     }
 
     public void setSleeping(boolean value) {
-        setMaskBit(MASK_INDEX, SLEEPING_BIT, value);
+        setMaskBit(OFFSET + 1, SLEEPING_BIT, value);
     }
 
     public boolean isFaceplanted() {
-        return getMaskBit(MASK_INDEX, FACEPLANTED_BIT);
+        return getMaskBit(OFFSET + 1, FACEPLANTED_BIT);
     }
 
     public void setFaceplanted(boolean value) {
-        setMaskBit(MASK_INDEX, FACEPLANTED_BIT, value);
+        setMaskBit(OFFSET + 1, FACEPLANTED_BIT, value);
     }
 
     public boolean isDefending() {
-        return getMaskBit(MASK_INDEX, DEFENDING_BIT);
+        return getMaskBit(OFFSET + 1, DEFENDING_BIT);
     }
 
     public void setDefending(boolean value) {
-        setMaskBit(MASK_INDEX, DEFENDING_BIT, value);
+        setMaskBit(OFFSET + 1, DEFENDING_BIT, value);
     }
 
     @Nullable
     public UUID getFirstUUID() {
-        return super.metadata.getIndex((byte) 18, null);
+        return super.metadata.getIndex(OFFSET + 2, null);
     }
 
     public void setFirstUUID(@Nullable UUID value) {
-        super.metadata.setIndex((byte) 18, Metadata.OptUUID(value));
+        super.metadata.setIndex(OFFSET + 2, Metadata.OptUUID(value));
     }
 
     @Nullable
     public UUID getSecondUUID() {
-        return super.metadata.getIndex((byte) 19, null);
+        return super.metadata.getIndex(OFFSET + 3, null);
     }
 
     public void setSecondUUID(@Nullable UUID value) {
-        super.metadata.setIndex((byte) 19, Metadata.OptUUID(value));
+        super.metadata.setIndex(OFFSET + 3, Metadata.OptUUID(value));
     }
 
     public enum Type {

src/main/java/net/minestom/server/entity/metadata/animal/HoglinMeta.java

@@ -5,17 +5,19 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class HoglinMeta extends AnimalMeta {
+    public static final byte OFFSET = AnimalMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     public HoglinMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
     }
 
     public boolean isImmuneToZombification() {
-        return super.metadata.getIndex((byte) 16, false);
+        return super.metadata.getIndex(OFFSET, false);
     }
 
     public void setImmuneToZombification(boolean value) {
-        super.metadata.setIndex((byte) 16, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET, Metadata.Boolean(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/animal/HorseMeta.java

@@ -5,17 +5,19 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class HorseMeta extends AbstractHorseMeta {
+    public static final byte OFFSET = AbstractHorseMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     public HorseMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
     }
 
     public Variant getVariant() {
-        return getVariantFromID(super.metadata.getIndex((byte) 18, 0));
+        return getVariantFromID(super.metadata.getIndex(OFFSET, 0));
     }
 
     public void setVariant(Variant variant) {
-        super.metadata.setIndex((byte) 18, Metadata.VarInt(getVariantID(variant.marking, variant.color)));
+        super.metadata.setIndex(OFFSET, Metadata.VarInt(getVariantID(variant.marking, variant.color)));
     }
 
     public static int getVariantID(@NotNull Marking marking, @NotNull Color color) {

src/main/java/net/minestom/server/entity/metadata/animal/LlamaMeta.java

@@ -5,33 +5,35 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class LlamaMeta extends ChestedHorseMeta {
+    public static final byte OFFSET = ChestedHorseMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 3;
 
     public LlamaMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
     }
 
     public int getStrength() {
-        return super.metadata.getIndex((byte) 19, 0);
+        return super.metadata.getIndex(OFFSET, 0);
     }
 
     public void setStrength(int value) {
-        super.metadata.setIndex((byte) 19, Metadata.VarInt(value));
+        super.metadata.setIndex(OFFSET, Metadata.VarInt(value));
     }
 
     public int getCarpetColor() {
-        return super.metadata.getIndex((byte) 20, -1);
+        return super.metadata.getIndex(OFFSET + 1, -1);
     }
 
     public void setCarpetColor(int value) {
-        super.metadata.setIndex((byte) 20, Metadata.VarInt(value));
+        super.metadata.setIndex(OFFSET + 1, Metadata.VarInt(value));
     }
 
     public Variant getVariant() {
-        return Variant.VALUES[super.metadata.getIndex((byte) 21, 0)];
+        return Variant.VALUES[super.metadata.getIndex(OFFSET + 2, 0)];
     }
 
     public void setVariant(Variant value) {
-        super.metadata.setIndex((byte) 21, Metadata.VarInt(value.ordinal()));
+        super.metadata.setIndex(OFFSET + 2, Metadata.VarInt(value.ordinal()));
     }
 
     public enum Variant {

src/main/java/net/minestom/server/entity/metadata/animal/MooshroomMeta.java

@@ -7,6 +7,8 @@ import org.jetbrains.annotations.NotNull;
 import java.util.Locale;
 
 public class MooshroomMeta extends CowMeta {
+    public static final byte OFFSET = CowMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     public MooshroomMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
@@ -14,11 +16,11 @@ public class MooshroomMeta extends CowMeta {
 
     @NotNull
     public Variant getVariant() {
-        return Variant.valueOf(super.metadata.getIndex((byte) 16, "red").toUpperCase(Locale.ROOT));
+        return Variant.valueOf(super.metadata.getIndex(OFFSET, "red").toUpperCase(Locale.ROOT));
     }
 
     public void setVariant(@NotNull Variant value) {
-        super.metadata.setIndex((byte) 16, Metadata.String(value.name().toLowerCase(Locale.ROOT)));
+        super.metadata.setIndex(OFFSET, Metadata.String(value.name().toLowerCase(Locale.ROOT)));
     }
 
     public enum Variant {

src/main/java/net/minestom/server/entity/metadata/animal/MuleMeta.java

@@ -5,6 +5,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class MuleMeta extends ChestedHorseMeta {
+    public static final byte OFFSET = ChestedHorseMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public MuleMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/animal/OcelotMeta.java

@@ -5,17 +5,19 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class OcelotMeta extends AnimalMeta {
+    public static final byte OFFSET = AnimalMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     public OcelotMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
     }
 
     public boolean isTrusting() {
-        return super.metadata.getIndex((byte) 16, false);
+        return super.metadata.getIndex(OFFSET, false);
     }
 
     public void setTrusting(boolean value) {
-        super.metadata.setIndex((byte) 16, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET, Metadata.Boolean(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/animal/PandaMeta.java

@@ -5,8 +5,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class PandaMeta extends AnimalMeta {
-
+    public static final byte OFFSET = AnimalMeta.MAX_OFFSET;
-    private final static byte MASK_INDEX = 21;
+    public static final byte MAX_OFFSET = OFFSET + 6;
 
     private final static byte SNEEZING_BIT = 0x02;
     private final static byte ROLLING_BIT = 0x04;
@@ -18,77 +18,77 @@ public class PandaMeta extends AnimalMeta {
     }
 
     public int getBreedTimer() {
-        return super.metadata.getIndex((byte) 16, 0);
+        return super.metadata.getIndex(OFFSET, 0);
     }
 
     public void setBreedTimer(int value) {
-        super.metadata.setIndex((byte) 16, Metadata.VarInt(value));
+        super.metadata.setIndex(OFFSET, Metadata.VarInt(value));
     }
 
     public int getSneezeTimer() {
-        return super.metadata.getIndex((byte) 17, 0);
+        return super.metadata.getIndex(OFFSET + 1, 0);
     }
 
     public void setSneezeTimer(int value) {
-        super.metadata.setIndex((byte) 17, Metadata.VarInt(value));
+        super.metadata.setIndex(OFFSET + 1, Metadata.VarInt(value));
     }
 
     public int getEatTimer() {
-        return super.metadata.getIndex((byte) 18, 0);
+        return super.metadata.getIndex(OFFSET + 2, 0);
     }
 
     public void setEatTimer(int value) {
-        super.metadata.setIndex((byte) 18, Metadata.VarInt(value));
+        super.metadata.setIndex(OFFSET + 2, Metadata.VarInt(value));
     }
 
     @NotNull
     public Gene getMainGene() {
-        return Gene.VALUES[super.metadata.getIndex((byte) 19, (byte) 0)];
+        return Gene.VALUES[super.metadata.getIndex(OFFSET + 3, (byte) 0)];
     }
 
     public void setMainGene(@NotNull Gene value) {
-        super.metadata.setIndex((byte) 19, Metadata.Byte((byte) value.ordinal()));
+        super.metadata.setIndex(OFFSET + 3, Metadata.Byte((byte) value.ordinal()));
     }
 
     @NotNull
     public Gene getHiddenGene() {
-        return Gene.VALUES[super.metadata.getIndex((byte) 20, (byte) 0)];
+        return Gene.VALUES[super.metadata.getIndex(OFFSET + 4, (byte) 0)];
     }
 
     public void setHiddenGene(@NotNull Gene value) {
-        super.metadata.setIndex((byte) 20, Metadata.Byte((byte) value.ordinal()));
+        super.metadata.setIndex(OFFSET + 4, Metadata.Byte((byte) value.ordinal()));
     }
 
     public boolean isSneezing() {
-        return getMaskBit(MASK_INDEX, SNEEZING_BIT);
+        return getMaskBit(OFFSET + 5, SNEEZING_BIT);
     }
 
     public void setSneezing(boolean value) {
-        setMaskBit(MASK_INDEX, SNEEZING_BIT, value);
+        setMaskBit(OFFSET + 5, SNEEZING_BIT, value);
     }
 
     public boolean isRolling() {
-        return getMaskBit(MASK_INDEX, ROLLING_BIT);
+        return getMaskBit(OFFSET + 5, ROLLING_BIT);
     }
 
     public void setRolling(boolean value) {
-        setMaskBit(MASK_INDEX, ROLLING_BIT, value);
+        setMaskBit(OFFSET + 5, ROLLING_BIT, value);
     }
 
     public boolean isSitting() {
-        return getMaskBit(MASK_INDEX, SITTING_BIT);
+        return getMaskBit(OFFSET + 5, SITTING_BIT);
     }
 
     public void setSitting(boolean value) {
-        setMaskBit(MASK_INDEX, SITTING_BIT, value);
+        setMaskBit(OFFSET + 5, SITTING_BIT, value);
     }
 
     public boolean isOnBack() {
-        return getMaskBit(MASK_INDEX, ON_BACK_BIT);
+        return getMaskBit(OFFSET + 5, ON_BACK_BIT);
     }
 
     public void setOnBack(boolean value) {
-        setMaskBit(MASK_INDEX, ON_BACK_BIT, value);
+        setMaskBit(OFFSET + 5, ON_BACK_BIT, value);
     }
 
     public enum Gene {

src/main/java/net/minestom/server/entity/metadata/animal/PigMeta.java

@@ -5,25 +5,27 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class PigMeta extends AnimalMeta {
+    public static final byte OFFSET = AnimalMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 2;
 
     public PigMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
     }
 
     public boolean isHasSaddle() {
-        return super.metadata.getIndex((byte) 16, false);
+        return super.metadata.getIndex(OFFSET, false);
     }
 
     public void setHasSaddle(boolean value) {
-        super.metadata.setIndex((byte) 16, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET, Metadata.Boolean(value));
     }
 
     public int getTimeToBoost() {
-        return super.metadata.getIndex((byte) 17, 0);
+        return super.metadata.getIndex(OFFSET + 1, 0);
     }
 
     public void setTimeToBoost(int value) {
-        super.metadata.getIndex((byte) 17, Metadata.VarInt(value));
+        super.metadata.getIndex(OFFSET + 1, Metadata.VarInt(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/animal/PolarBearMeta.java

@@ -5,17 +5,19 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class PolarBearMeta extends AnimalMeta {
+    public static final byte OFFSET = AnimalMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     public PolarBearMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
     }
 
     public boolean isStandingUp() {
-        return super.metadata.getIndex((byte) 16, false);
+        return super.metadata.getIndex(OFFSET, false);
     }
 
     public void setStandingUp(boolean value) {
-        super.metadata.setIndex((byte) 16, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET, Metadata.Boolean(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/animal/RabbitMeta.java

@@ -5,6 +5,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class RabbitMeta extends AnimalMeta {
+    public static final byte OFFSET = AnimalMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     public RabbitMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
@@ -12,7 +14,7 @@ public class RabbitMeta extends AnimalMeta {
 
     @NotNull
     public Type getType() {
-        int id = super.metadata.getIndex((byte) 16, 0);
+        int id = super.metadata.getIndex(OFFSET, 0);
         if (id == 99) {
             return Type.KILLER_BUNNY;
         }
@@ -21,7 +23,7 @@ public class RabbitMeta extends AnimalMeta {
 
     public void setType(@NotNull Type value) {
         int id = value == Type.KILLER_BUNNY ? 99 : value.ordinal();
-        super.metadata.setIndex((byte) 16, Metadata.VarInt(id));
+        super.metadata.setIndex(OFFSET, Metadata.VarInt(id));
     }
 
     public enum Type {

src/main/java/net/minestom/server/entity/metadata/animal/SheepMeta.java

@@ -5,8 +5,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class SheepMeta extends AnimalMeta {
-
+    public static final byte OFFSET = AnimalMeta.MAX_OFFSET;
-    private final static byte MASK_INDEX = 16;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     private final static byte COLOR_BITS = 0x0F;
     private final static byte SHEARED_BIT = 0x10;
@@ -16,25 +16,25 @@ public class SheepMeta extends AnimalMeta {
     }
 
     public int getColor() {
-        return getMask(MASK_INDEX) & COLOR_BITS;
+        return getMask(OFFSET) & COLOR_BITS;
     }
 
     public void setColor(byte color) {
-        byte before = getMask(MASK_INDEX);
+        byte before = getMask(OFFSET);
         byte mask = before;
         mask &= ~COLOR_BITS;
         mask |= (color & COLOR_BITS);
         if (mask != before) {
-            setMask(MASK_INDEX, mask);
+            setMask(OFFSET, mask);
         }
     }
 
     public boolean isSheared() {
-        return getMaskBit(MASK_INDEX, SHEARED_BIT);
+        return getMaskBit(OFFSET, SHEARED_BIT);
     }
 
     public void setSheared(boolean value) {
-        setMaskBit(MASK_INDEX, SHEARED_BIT, value);
+        setMaskBit(OFFSET, SHEARED_BIT, value);
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/animal/SkeletonHorseMeta.java

@@ -5,6 +5,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class SkeletonHorseMeta extends AbstractHorseMeta {
+    public static final byte OFFSET = AbstractHorseMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public SkeletonHorseMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/animal/StriderMeta.java

@@ -5,33 +5,35 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class StriderMeta extends AnimalMeta {
+    public static final byte OFFSET = AnimalMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 3;
 
     public StriderMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
     }
 
     public int getTimeToBoost() {
-        return super.metadata.getIndex((byte) 16, 0);
+        return super.metadata.getIndex(OFFSET, 0);
     }
 
     public void setTimeToBoost(int value) {
-        super.metadata.setIndex((byte) 16, Metadata.VarInt(value));
+        super.metadata.setIndex(OFFSET, Metadata.VarInt(value));
     }
 
     public boolean isShaking() {
-        return super.metadata.getIndex((byte) 17, false);
+        return super.metadata.getIndex(OFFSET + 1, false);
     }
 
     public void setShaking(boolean value) {
-        super.metadata.setIndex((byte) 17, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET + 1, Metadata.Boolean(value));
     }
 
     public boolean isHasSaddle() {
-        return super.metadata.getIndex((byte) 18, false);
+        return super.metadata.getIndex(OFFSET + 2, false);
     }
 
     public void setHasSaddle(boolean value) {
-        super.metadata.setIndex((byte) 18, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET + 2, Metadata.Boolean(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/animal/TurtleMeta.java

@@ -6,6 +6,8 @@ import net.minestom.server.utils.BlockPosition;
 import org.jetbrains.annotations.NotNull;
 
 public class TurtleMeta extends AnimalMeta {
+    public static final byte OFFSET = AnimalMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 6;
 
     public TurtleMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
@@ -13,52 +15,52 @@ public class TurtleMeta extends AnimalMeta {
 
     @NotNull
     public BlockPosition getHomePosition() {
-        return super.metadata.getIndex((byte) 16, new BlockPosition(0, 0, 0));
+        return super.metadata.getIndex(OFFSET, new BlockPosition(0, 0, 0));
     }
 
     public void setBlockPosition(@NotNull BlockPosition value) {
-        super.metadata.setIndex((byte) 16, Metadata.Position(value));
+        super.metadata.setIndex(OFFSET, Metadata.Position(value));
     }
 
     public boolean isHasEgg() {
-        return super.metadata.getIndex((byte) 17, false);
+        return super.metadata.getIndex(OFFSET + 1, false);
     }
 
     public void setHasEgg(boolean value) {
-        super.metadata.setIndex((byte) 17, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET + 1, Metadata.Boolean(value));
     }
 
     public boolean isLayingEgg() {
-        return super.metadata.getIndex((byte) 18, false);
+        return super.metadata.getIndex(OFFSET + 2, false);
     }
 
     public void setLayingEgg(boolean value) {
-        super.metadata.setIndex((byte) 18, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET + 2, Metadata.Boolean(value));
     }
 
     @NotNull
     public BlockPosition getTravelPosition() {
-        return super.metadata.getIndex((byte) 19, new BlockPosition(0, 0, 0));
+        return super.metadata.getIndex(OFFSET + 3, new BlockPosition(0, 0, 0));
     }
 
     public void setTravelPosition(@NotNull BlockPosition value) {
-        super.metadata.setIndex((byte) 19, Metadata.Position(value));
+        super.metadata.setIndex(OFFSET + 3, Metadata.Position(value));
     }
 
     public boolean isGoingHome() {
-        return super.metadata.getIndex((byte) 20, false);
+        return super.metadata.getIndex(OFFSET + 4, false);
     }
 
     public void setGoingHome(boolean value) {
-        super.metadata.setIndex((byte) 20, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET + 4, Metadata.Boolean(value));
     }
 
     public boolean isTravelling() {
-        return super.metadata.getIndex((byte) 21, false);
+        return super.metadata.getIndex(OFFSET + 5, false);
     }
 
     public void setTravelling(boolean value) {
-        super.metadata.setIndex((byte) 21, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET + 5, Metadata.Boolean(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/animal/ZombieHorseMeta.java

@@ -5,6 +5,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class ZombieHorseMeta extends AbstractHorseMeta {
+    public static final byte OFFSET = AbstractHorseMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public ZombieHorseMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/animal/tameable/CatMeta.java

@@ -2,9 +2,12 @@ package net.minestom.server.entity.metadata.animal.tameable;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.animal.AnimalMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class CatMeta extends TameableAnimalMeta {
+    public static final byte OFFSET = TameableAnimalMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 4;
 
     public CatMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
@@ -12,35 +15,35 @@ public class CatMeta extends TameableAnimalMeta {
 
     @NotNull
     public Color getColor() {
-        return Color.VALUES[super.metadata.getIndex((byte) 18, 1)];
+        return Color.VALUES[super.metadata.getIndex(OFFSET, 1)];
     }
 
     public void setColor(@NotNull Color value) {
-        super.metadata.setIndex((byte) 18, Metadata.VarInt(value.ordinal()));
+        super.metadata.setIndex(OFFSET, Metadata.VarInt(value.ordinal()));
     }
 
     public boolean isLying() {
-        return super.metadata.getIndex((byte) 19, false);
+        return super.metadata.getIndex(OFFSET + 1, false);
     }
 
     public void setLying(boolean value) {
-        super.metadata.setIndex((byte) 19, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET + 1, Metadata.Boolean(value));
     }
 
     public boolean isRelaxed() {
-        return super.metadata.getIndex((byte) 20, false);
+        return super.metadata.getIndex(OFFSET + 2, false);
     }
 
     public void setRelaxed(boolean value) {
-        super.metadata.setIndex((byte) 20, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET + 2, Metadata.Boolean(value));
     }
 
     public int getCollarColor() {
-        return super.metadata.getIndex((byte) 21, 14);
+        return super.metadata.getIndex(OFFSET + 3, 14);
     }
 
     public void setCollarColor(int value) {
-        super.metadata.setIndex((byte) 21, Metadata.VarInt(value));
+        super.metadata.setIndex(OFFSET + 3, Metadata.VarInt(value));
     }
 
     public enum Color {

src/main/java/net/minestom/server/entity/metadata/animal/tameable/ParrotMeta.java

@@ -2,9 +2,12 @@ package net.minestom.server.entity.metadata.animal.tameable;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.animal.AnimalMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class ParrotMeta extends TameableAnimalMeta {
+    public static final byte OFFSET = TameableAnimalMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     public ParrotMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
@@ -12,11 +15,11 @@ public class ParrotMeta extends TameableAnimalMeta {
 
     @NotNull
     public Color getColor() {
-        return Color.VALUES[super.metadata.getIndex((byte) 18, 0)];
+        return Color.VALUES[super.metadata.getIndex(OFFSET, 0)];
     }
 
     public void setColor(@NotNull Color value) {
-        super.metadata.setIndex((byte) 18, Metadata.VarInt(value.ordinal()));
+        super.metadata.setIndex(OFFSET, Metadata.VarInt(value.ordinal()));
     }
 
     public enum Color {

src/main/java/net/minestom/server/entity/metadata/animal/tameable/TameableAnimalMeta.java

@@ -8,8 +8,8 @@ import org.jetbrains.annotations.NotNull;
 import java.util.UUID;
 
 public class TameableAnimalMeta extends AnimalMeta {
-
+    public static final byte OFFSET = AnimalMeta.MAX_OFFSET;
-    private final static byte MASK_INDEX = 16;
+    public static final byte MAX_OFFSET = OFFSET + 2;
 
     private final static byte SITTING_BIT = 0x01;
     private final static byte TAMED_BIT = 0x04;
@@ -19,28 +19,28 @@ public class TameableAnimalMeta extends AnimalMeta {
     }
 
     public boolean isSitting() {
-        return getMaskBit(MASK_INDEX, SITTING_BIT);
+        return getMaskBit(OFFSET, SITTING_BIT);
     }
 
     public void setSitting(boolean value) {
-        setMaskBit(MASK_INDEX, SITTING_BIT, value);
+        setMaskBit(OFFSET, SITTING_BIT, value);
     }
 
     public boolean isTamed() {
-        return getMaskBit(MASK_INDEX, TAMED_BIT);
+        return getMaskBit(OFFSET, TAMED_BIT);
     }
 
     public void setTamed(boolean value) {
-        setMaskBit(MASK_INDEX, TAMED_BIT, value);
+        setMaskBit(OFFSET, TAMED_BIT, value);
     }
 
     @NotNull
     public UUID getOwner() {
-        return super.metadata.getIndex((byte) 17, null);
+        return super.metadata.getIndex(OFFSET + 1, null);
     }
 
     public void setOwner(@NotNull UUID value) {
-        super.metadata.setIndex((byte) 17, Metadata.OptUUID(value));
+        super.metadata.setIndex(OFFSET + 1, Metadata.OptUUID(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/animal/tameable/WolfMeta.java

@@ -5,33 +5,35 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class WolfMeta extends TameableAnimalMeta {
+    public static final byte OFFSET = TameableAnimalMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 3;
 
     public WolfMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
     }
 
     public boolean isBegging() {
-        return super.metadata.getIndex((byte) 18, false);
+        return super.metadata.getIndex(OFFSET, false);
     }
 
     public void setBegging(boolean value) {
-        super.metadata.setIndex((byte) 18, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET, Metadata.Boolean(value));
     }
 
     public int getCollarColor() {
-        return super.metadata.getIndex((byte) 19, 14);
+        return super.metadata.getIndex(OFFSET + 1, 14);
     }
 
     public void setCollarColor(int value) {
-        super.metadata.setIndex((byte) 19, Metadata.VarInt(value));
+        super.metadata.setIndex(OFFSET + 1, Metadata.VarInt(value));
     }
 
     public int getAngerTime() {
-        return super.metadata.getIndex((byte) 20, 0);
+        return super.metadata.getIndex(OFFSET + 2, 0);
     }
 
     public void setAngerTime(int value) {
-        super.metadata.setIndex((byte) 20, Metadata.VarInt(value));
+        super.metadata.setIndex(OFFSET + 2, Metadata.VarInt(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/arrow/AbstractArrowMeta.java

@@ -3,11 +3,12 @@ package net.minestom.server.entity.metadata.arrow;
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
 import net.minestom.server.entity.metadata.EntityMeta;
+import net.minestom.server.entity.metadata.animal.tameable.TameableAnimalMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class AbstractArrowMeta extends EntityMeta {
-
+    public static final byte OFFSET = EntityMeta.MAX_OFFSET;
-    private final static byte MASK_INDEX = 7;
+    public static final byte MAX_OFFSET = OFFSET + 2;
 
     private final static byte CRITICAL_BIT = 0x01;
     private final static byte NO_CLIP_BIT = 0x01;
@@ -17,27 +18,27 @@ public class AbstractArrowMeta extends EntityMeta {
     }
 
     public boolean isCritical() {
-        return getMaskBit(MASK_INDEX, CRITICAL_BIT);
+        return getMaskBit(OFFSET, CRITICAL_BIT);
     }
 
     public void setCritical(boolean value) {
-        setMaskBit(MASK_INDEX, CRITICAL_BIT, value);
+        setMaskBit(OFFSET, CRITICAL_BIT, value);
     }
 
     public boolean isNoClip() {
-        return getMaskBit(MASK_INDEX, NO_CLIP_BIT);
+        return getMaskBit(OFFSET, NO_CLIP_BIT);
     }
 
     public void setNoClip(boolean value) {
-        setMaskBit(MASK_INDEX, NO_CLIP_BIT, value);
+        setMaskBit(OFFSET, NO_CLIP_BIT, value);
     }
 
     public byte getPiercingLevel() {
-        return super.metadata.getIndex((byte) 8, (byte) 0);
+        return super.metadata.getIndex(OFFSET + 1, (byte) 0);
     }
 
     public void setPiercingLevel(byte value) {
-        super.metadata.setIndex((byte) 8, Metadata.Byte(value));
+        super.metadata.setIndex(OFFSET + 1, Metadata.Byte(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/arrow/ArrowMeta.java

@@ -4,10 +4,13 @@ import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
 import net.minestom.server.entity.metadata.ObjectDataProvider;
 import net.minestom.server.entity.metadata.ProjectileMeta;
+import net.minestom.server.entity.metadata.animal.tameable.TameableAnimalMeta;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 public class ArrowMeta extends AbstractArrowMeta implements ObjectDataProvider, ProjectileMeta {
+    public static final byte OFFSET = AbstractArrowMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     private Entity shooter;
 
@@ -16,11 +19,11 @@ public class ArrowMeta extends AbstractArrowMeta implements ObjectDataProvider,
     }
 
     public int getColor() {
-        return super.metadata.getIndex((byte) 9, -1);
+        return super.metadata.getIndex(OFFSET, -1);
     }
 
     public void setColor(int value) {
-        super.metadata.setIndex((byte) 9, Metadata.VarInt(value));
+        super.metadata.setIndex(OFFSET, Metadata.VarInt(value));
     }
 
     @Override

src/main/java/net/minestom/server/entity/metadata/arrow/SpectralArrowMeta.java

@@ -8,6 +8,8 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 public class SpectralArrowMeta extends AbstractArrowMeta implements ObjectDataProvider, ProjectileMeta {
+    public static final byte OFFSET = AbstractArrowMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     private Entity shooter;
 

src/main/java/net/minestom/server/entity/metadata/arrow/ThrownTridentMeta.java

@@ -5,25 +5,27 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class ThrownTridentMeta extends AbstractArrowMeta {
+    public static final byte OFFSET = AbstractArrowMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 2;
 
     public ThrownTridentMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
     }
 
     public int getLoyaltyLevel() {
-        return super.metadata.getIndex((byte) 9, 0);
+        return super.metadata.getIndex(OFFSET, 0);
     }
 
     public void setLoyaltyLevel(int value) {
-        super.metadata.setIndex((byte) 9, Metadata.VarInt(value));
+        super.metadata.setIndex(OFFSET, Metadata.VarInt(value));
     }
 
     public boolean isHasEnchantmentGlint() {
-        return super.metadata.getIndex((byte) 10, false);
+        return super.metadata.getIndex(OFFSET + 1, false);
     }
 
     public void setHasEnchantmentGlint(boolean value) {
-        super.metadata.setIndex((byte) 10, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET + 1, Metadata.Boolean(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/flying/FlyingMeta.java

@@ -3,9 +3,12 @@ package net.minestom.server.entity.metadata.flying;
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
 import net.minestom.server.entity.metadata.MobMeta;
+import net.minestom.server.entity.metadata.arrow.AbstractArrowMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class FlyingMeta extends MobMeta {
+    public static final byte OFFSET = MobMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     protected FlyingMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/flying/GhastMeta.java

@@ -2,20 +2,23 @@ package net.minestom.server.entity.metadata.flying;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.MobMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class GhastMeta extends FlyingMeta {
+    public static final byte OFFSET = FlyingMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     public GhastMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
     }
 
     public boolean isAttacking() {
-        return super.metadata.getIndex((byte) 15, false);
+        return super.metadata.getIndex(OFFSET, false);
     }
 
     public void setAttacking(boolean value) {
-        super.metadata.setIndex((byte) 15, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET, Metadata.Boolean(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/flying/PhantomMeta.java

@@ -2,20 +2,23 @@ package net.minestom.server.entity.metadata.flying;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.MobMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class PhantomMeta extends FlyingMeta {
+    public static final byte OFFSET = FlyingMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     public PhantomMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
     }
 
     public int getSize() {
-        return super.metadata.getIndex((byte) 15, 0);
+        return super.metadata.getIndex(OFFSET, 0);
     }
 
     public void setSize(int value) {
-        super.metadata.setIndex((byte) 15, Metadata.VarInt(value));
+        super.metadata.setIndex(OFFSET, Metadata.VarInt(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/golem/AbstractGolemMeta.java

@@ -2,10 +2,13 @@ package net.minestom.server.entity.metadata.golem;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.MobMeta;
 import net.minestom.server.entity.metadata.PathfinderMobMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class AbstractGolemMeta extends PathfinderMobMeta {
+    public static final byte OFFSET = PathfinderMobMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     protected AbstractGolemMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/golem/IronGolemMeta.java

@@ -2,11 +2,12 @@ package net.minestom.server.entity.metadata.golem;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.MobMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class IronGolemMeta extends AbstractGolemMeta {
-
+    public static final byte OFFSET = AbstractGolemMeta.MAX_OFFSET;
-    private final static byte MASK_INDEX = 15;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     private final static byte PLAYER_CREATED_BIT = 0x01;
 
@@ -15,11 +16,11 @@ public class IronGolemMeta extends AbstractGolemMeta {
     }
 
     public boolean isPlayerCreated() {
-        return getMaskBit(MASK_INDEX, PLAYER_CREATED_BIT);
+        return getMaskBit(OFFSET, PLAYER_CREATED_BIT);
     }
 
     public void setPlayerCreated(boolean value) {
-        setMaskBit(MASK_INDEX, PLAYER_CREATED_BIT, value);
+        setMaskBit(OFFSET, PLAYER_CREATED_BIT, value);
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/golem/ShulkerMeta.java

@@ -7,41 +7,43 @@ import net.minestom.server.utils.Direction;
 import org.jetbrains.annotations.NotNull;
 
 public class ShulkerMeta extends AbstractGolemMeta {
+    public static final byte OFFSET = AbstractGolemMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 4;
 
     public ShulkerMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
     }
 
     public Direction getAttachFace() {
-        return super.metadata.getIndex((byte) 15, Direction.DOWN);
+        return super.metadata.getIndex(OFFSET, Direction.DOWN);
     }
 
     public void setAttachFace(Direction value) {
-        super.metadata.setIndex((byte) 15, Metadata.Direction(value));
+        super.metadata.setIndex(OFFSET, Metadata.Direction(value));
     }
 
     public BlockPosition getAttachmentPosition() {
-        return super.metadata.getIndex((byte) 16, null);
+        return super.metadata.getIndex(OFFSET + 1, null);
     }
 
     public void setAttachmentPosition(BlockPosition value) {
-        super.metadata.setIndex((byte) 16, Metadata.OptPosition(value));
+        super.metadata.setIndex(OFFSET + 1, Metadata.OptPosition(value));
     }
 
     public byte getShieldHeight() {
-        return super.metadata.getIndex((byte) 17, (byte) 0);
+        return super.metadata.getIndex(OFFSET + 2, (byte) 0);
     }
 
     public void setShieldHeight(byte value) {
-        super.metadata.setIndex((byte) 17, Metadata.Byte(value));
+        super.metadata.setIndex(OFFSET + 2, Metadata.Byte(value));
     }
 
     public byte getColor() {
-        return super.metadata.getIndex((byte) 18, (byte) 10);
+        return super.metadata.getIndex(OFFSET + 3, (byte) 10);
     }
 
     public void setColor(byte value) {
-        super.metadata.setIndex((byte) 18, Metadata.Byte(value));
+        super.metadata.setIndex(OFFSET + 3, Metadata.Byte(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/golem/SnowGolemMeta.java

@@ -5,17 +5,19 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class SnowGolemMeta extends AbstractGolemMeta {
+    public static final byte OFFSET = AbstractGolemMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     public SnowGolemMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
     }
 
     public boolean isHasPumpkinHat() {
-        return super.metadata.getIndex((byte) 15, (byte) 0x10) == (byte) 0x10;
+        return super.metadata.getIndex(OFFSET, (byte) 0x10) == (byte) 0x10;
     }
 
     public void setHasPumpkinHat(boolean value) {
-        super.metadata.setIndex((byte) 15, Metadata.Byte(value ? (byte) 0x10 : (byte) 0x00));
+        super.metadata.setIndex(OFFSET, Metadata.Byte(value ? (byte) 0x10 : (byte) 0x00));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/item/EyeOfEnderMeta.java

@@ -6,6 +6,8 @@ import net.minestom.server.item.Material;
 import org.jetbrains.annotations.NotNull;
 
 public class EyeOfEnderMeta extends ItemContainingMeta {
+    public static final byte OFFSET = ItemContainingMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public EyeOfEnderMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata, Material.ENDER_EYE);

src/main/java/net/minestom/server/entity/metadata/item/FireballMeta.java

@@ -4,11 +4,14 @@ import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
 import net.minestom.server.entity.metadata.ObjectDataProvider;
 import net.minestom.server.entity.metadata.ProjectileMeta;
+import net.minestom.server.entity.metadata.golem.AbstractGolemMeta;
 import net.minestom.server.item.Material;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 public class FireballMeta extends ItemContainingMeta implements ObjectDataProvider, ProjectileMeta {
+    public static final byte OFFSET = ItemContainingMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     private Entity shooter;
 

src/main/java/net/minestom/server/entity/metadata/item/ItemContainingMeta.java

@@ -3,11 +3,14 @@ package net.minestom.server.entity.metadata.item;
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
 import net.minestom.server.entity.metadata.EntityMeta;
+import net.minestom.server.entity.metadata.golem.AbstractGolemMeta;
 import net.minestom.server.item.ItemStack;
 import net.minestom.server.item.Material;
 import org.jetbrains.annotations.NotNull;
 
 class ItemContainingMeta extends EntityMeta {
+    public static final byte OFFSET = EntityMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     private final ItemStack defaultItem;
 
@@ -18,11 +21,11 @@ class ItemContainingMeta extends EntityMeta {
 
     @NotNull
     public ItemStack getItem() {
-        return super.metadata.getIndex((byte) 7, this.defaultItem);
+        return super.metadata.getIndex(OFFSET, this.defaultItem);
     }
 
     public void setItem(@NotNull ItemStack item) {
-        super.metadata.setIndex((byte) 7, Metadata.Slot(item));
+        super.metadata.setIndex(OFFSET, Metadata.Slot(item));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/item/ItemEntityMeta.java

@@ -7,6 +7,8 @@ import net.minestom.server.item.Material;
 import org.jetbrains.annotations.NotNull;
 
 public class ItemEntityMeta extends ItemContainingMeta implements ObjectDataProvider {
+    public static final byte OFFSET = ItemContainingMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public ItemEntityMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata, Material.AIR);

src/main/java/net/minestom/server/entity/metadata/item/SmallFireballMeta.java

@@ -9,6 +9,8 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 public class SmallFireballMeta extends ItemContainingMeta implements ObjectDataProvider, ProjectileMeta {
+    public static final byte OFFSET = ItemContainingMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     private Entity shooter;
 

src/main/java/net/minestom/server/entity/metadata/item/SnowballMeta.java

@@ -6,6 +6,8 @@ import net.minestom.server.item.Material;
 import org.jetbrains.annotations.NotNull;
 
 public class SnowballMeta extends ItemContainingMeta {
+    public static final byte OFFSET = ItemContainingMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public SnowballMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata, Material.SNOWBALL);

src/main/java/net/minestom/server/entity/metadata/item/ThrownEggMeta.java

@@ -6,6 +6,8 @@ import net.minestom.server.item.Material;
 import org.jetbrains.annotations.NotNull;
 
 public class ThrownEggMeta extends ItemContainingMeta {
+    public static final byte OFFSET = ItemContainingMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public ThrownEggMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata, Material.EGG);

src/main/java/net/minestom/server/entity/metadata/item/ThrownEnderPearlMeta.java

@@ -6,6 +6,8 @@ import net.minestom.server.item.Material;
 import org.jetbrains.annotations.NotNull;
 
 public class ThrownEnderPearlMeta extends ItemContainingMeta {
+    public static final byte OFFSET = ItemContainingMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public ThrownEnderPearlMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata, Material.ENDER_PEARL);

src/main/java/net/minestom/server/entity/metadata/item/ThrownExperienceBottleMeta.java

@@ -6,6 +6,8 @@ import net.minestom.server.item.Material;
 import org.jetbrains.annotations.NotNull;
 
 public class ThrownExperienceBottleMeta extends ItemContainingMeta {
+    public static final byte OFFSET = ItemContainingMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public ThrownExperienceBottleMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata, Material.EXPERIENCE_BOTTLE);

src/main/java/net/minestom/server/entity/metadata/item/ThrownPotionMeta.java

@@ -6,6 +6,8 @@ import net.minestom.server.item.Material;
 import org.jetbrains.annotations.NotNull;
 
 public class ThrownPotionMeta extends ItemContainingMeta {
+    public static final byte OFFSET = ItemContainingMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public ThrownPotionMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata, Material.AIR);

src/main/java/net/minestom/server/entity/metadata/minecart/AbstractMinecartContainerMeta.java

@@ -5,6 +5,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public abstract class AbstractMinecartContainerMeta extends AbstractMinecartMeta {
+    public static final byte OFFSET = AbstractMinecartMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     protected AbstractMinecartContainerMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/minecart/AbstractMinecartMeta.java

@@ -7,50 +7,52 @@ import net.minestom.server.entity.metadata.ObjectDataProvider;
 import org.jetbrains.annotations.NotNull;
 
 public abstract class AbstractMinecartMeta extends EntityMeta implements ObjectDataProvider {
+    public static final byte OFFSET = EntityMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 6;
 
     protected AbstractMinecartMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
     }
 
     public int getShakingPower() {
-        return super.metadata.getIndex((byte) 7, 0);
+        return super.metadata.getIndex(OFFSET, 0);
     }
 
     public void setShakingPower(int value) {
-        super.metadata.setIndex((byte) 7, Metadata.VarInt(value));
+        super.metadata.setIndex(OFFSET, Metadata.VarInt(value));
     }
 
     public int getShakingDirection() {
-        return super.metadata.getIndex((byte) 8, 1);
+        return super.metadata.getIndex(OFFSET + 1, 1);
     }
 
     public void setShakingDirection(int value) {
-        super.metadata.setIndex((byte) 8, Metadata.VarInt(value));
+        super.metadata.setIndex(OFFSET + 1, Metadata.VarInt(value));
     }
 
     public float getShakingMultiplier() {
-        return super.metadata.getIndex((byte) 9, 0F);
+        return super.metadata.getIndex(OFFSET + 2, 0F);
     }
 
     public void setShakingMultiplier(float value) {
-        super.metadata.setIndex((byte) 9, Metadata.Float(value));
+        super.metadata.setIndex(OFFSET + 2, Metadata.Float(value));
     }
 
     public int getCustomBlockIdAndDamage() {
-        return super.metadata.getIndex((byte) 10, 0);
+        return super.metadata.getIndex(OFFSET + 3, 0);
     }
 
     public void setCustomBlockIdAndDamage(int value) {
-        super.metadata.setIndex((byte) 10, Metadata.VarInt(value));
+        super.metadata.setIndex(OFFSET + 3, Metadata.VarInt(value));
     }
 
     // in 16th of a block
     public int getCustomBlockYPosition() {
-        return super.metadata.getIndex((byte) 11, 6);
+        return super.metadata.getIndex(OFFSET + 4, 6);
     }
 
     public void setCustomBlockYPosition(int value) {
-        super.metadata.setIndex((byte) 11, Metadata.VarInt(value));
+        super.metadata.setIndex(OFFSET + 4, Metadata.VarInt(value));
     }
 
     @Override

src/main/java/net/minestom/server/entity/metadata/minecart/ChestMinecartMeta.java

@@ -5,6 +5,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class ChestMinecartMeta extends AbstractMinecartContainerMeta {
+    public static final byte OFFSET = AbstractMinecartContainerMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public ChestMinecartMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/minecart/CommandBlockMinecartMeta.java

@@ -7,6 +7,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class CommandBlockMinecartMeta extends AbstractMinecartMeta {
+    public static final byte OFFSET = AbstractMinecartMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 2;
 
     public CommandBlockMinecartMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
@@ -14,11 +16,11 @@ public class CommandBlockMinecartMeta extends AbstractMinecartMeta {
 
     @NotNull
     public String getCommand() {
-        return super.metadata.getIndex((byte) 13, "");
+        return super.metadata.getIndex(OFFSET, "");
     }
 
     public void setCommand(@NotNull String value) {
-        super.metadata.setIndex((byte) 13, Metadata.String(value));
+        super.metadata.setIndex(OFFSET, Metadata.String(value));
     }
 
     /**
@@ -32,7 +34,7 @@ public class CommandBlockMinecartMeta extends AbstractMinecartMeta {
 
     @NotNull
     public Component getLastOutput() {
-        return super.metadata.getIndex((byte) 14, Component.empty());
+        return super.metadata.getIndex(OFFSET + 1, Component.empty());
     }
 
     /**
@@ -44,7 +46,7 @@ public class CommandBlockMinecartMeta extends AbstractMinecartMeta {
     }
 
     public void setLastOutput(@NotNull Component value) {
-        super.metadata.setIndex((byte) 14, Metadata.Chat(value));
+        super.metadata.setIndex(OFFSET + 1, Metadata.Chat(value));
     }
 
     @Override

src/main/java/net/minestom/server/entity/metadata/minecart/FurnaceMinecartMeta.java

@@ -5,17 +5,19 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class FurnaceMinecartMeta extends AbstractMinecartMeta {
+    public static final byte OFFSET = AbstractMinecartMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     public FurnaceMinecartMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
     }
 
     public boolean isHasFuel() {
-        return super.metadata.getIndex((byte) 13, false);
+        return super.metadata.getIndex(OFFSET, false);
     }
 
     public void setHasFuel(boolean value) {
-        super.metadata.setIndex((byte) 13, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET, Metadata.Boolean(value));
     }
 
     @Override

src/main/java/net/minestom/server/entity/metadata/minecart/HopperMinecartMeta.java

@@ -5,6 +5,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class HopperMinecartMeta extends AbstractMinecartContainerMeta {
+    public static final byte OFFSET = AbstractMinecartContainerMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public HopperMinecartMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/minecart/MinecartMeta.java

@@ -5,6 +5,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class MinecartMeta extends AbstractMinecartMeta {
+    public static final byte OFFSET = AbstractMinecartMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public MinecartMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/minecart/SpawnerMinecartMeta.java

@@ -5,6 +5,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class SpawnerMinecartMeta extends AbstractMinecartMeta {
+    public static final byte OFFSET = AbstractMinecartMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public SpawnerMinecartMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/minecart/TntMinecartMeta.java

@@ -5,6 +5,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class TntMinecartMeta extends AbstractMinecartMeta {
+    public static final byte OFFSET = AbstractMinecartMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public TntMinecartMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/monster/BasePiglinMeta.java

@@ -5,17 +5,19 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class BasePiglinMeta extends MonsterMeta {
+    public static final byte OFFSET = MonsterMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     protected BasePiglinMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
     }
 
     public boolean isImmuneToZombification() {
-        return super.metadata.getIndex((byte) 15, false);
+        return super.metadata.getIndex(OFFSET, false);
     }
 
     public void setImmuneToZombification(boolean value) {
-        super.metadata.setIndex((byte) 15, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET, Metadata.Boolean(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/monster/BlazeMeta.java

@@ -5,8 +5,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class BlazeMeta extends MonsterMeta {
-
+    public static final byte OFFSET = MonsterMeta.MAX_OFFSET;
-    private final static byte MASK_INDEX = 15;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     private final static byte ON_FIRE_BIT = 0x01;
 
@@ -15,11 +15,11 @@ public class BlazeMeta extends MonsterMeta {
     }
 
     public boolean isOnFire() {
-        return getMaskBit(MASK_INDEX, ON_FIRE_BIT);
+        return getMaskBit(OFFSET, ON_FIRE_BIT);
     }
 
     public void setOnFire(boolean value) {
-        setMaskBit(MASK_INDEX, ON_FIRE_BIT, value);
+        setMaskBit(OFFSET, ON_FIRE_BIT, value);
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/monster/CaveSpiderMeta.java

@@ -5,6 +5,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class CaveSpiderMeta extends SpiderMeta {
+    public static final byte OFFSET = SpiderMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public CaveSpiderMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/monster/CreeperMeta.java

@@ -5,6 +5,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class CreeperMeta extends MonsterMeta {
+    public static final byte OFFSET = MonsterMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 3;
 
     public CreeperMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
@@ -12,28 +14,28 @@ public class CreeperMeta extends MonsterMeta {
 
     @NotNull
     public State getState() {
-        int id = super.metadata.getIndex((byte) 15, -1);
+        int id = super.metadata.getIndex(OFFSET, -1);
         return id == -1 ? State.IDLE : State.FUSE;
     }
 
     public void setState(@NotNull State value) {
-        super.metadata.setIndex((byte) 15, Metadata.VarInt(value == State.IDLE ? -1 : 1));
+        super.metadata.setIndex(OFFSET, Metadata.VarInt(value == State.IDLE ? -1 : 1));
     }
 
     public boolean isCharged() {
-        return super.metadata.getIndex((byte) 16, false);
+        return super.metadata.getIndex(OFFSET + 1, false);
     }
 
     public void setCharged(boolean value) {
-        super.metadata.setIndex((byte) 16, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET + 1, Metadata.Boolean(value));
     }
 
     public boolean isIgnited() {
-        return super.metadata.getIndex((byte) 17, false);
+        return super.metadata.getIndex(OFFSET + 2, false);
     }
 
     public void setIgnited(boolean value) {
-        super.metadata.setIndex((byte) 17, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET + 2, Metadata.Boolean(value));
     }
 
     public enum State {

src/main/java/net/minestom/server/entity/metadata/monster/ElderGuardianMeta.java

@@ -5,6 +5,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class ElderGuardianMeta extends GuardianMeta {
+    public static final byte OFFSET = GuardianMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public ElderGuardianMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/monster/EndermanMeta.java

@@ -6,33 +6,35 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 public class EndermanMeta extends MonsterMeta {
+    public static final byte OFFSET = MonsterMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 3;
 
     public EndermanMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
     }
 
     public Integer getCarriedBlockID() {
-        return super.metadata.getIndex((byte) 15, null);
+        return super.metadata.getIndex(OFFSET, null);
     }
 
     public void setCarriedBlockID(@Nullable Integer value) {
-        super.metadata.setIndex((byte) 15, Metadata.OptBlockID(value));
+        super.metadata.setIndex(OFFSET, Metadata.OptBlockID(value));
     }
 
     public boolean isScreaming() {
-        return super.metadata.getIndex((byte) 16, false);
+        return super.metadata.getIndex(OFFSET + 1, false);
     }
 
     public void setScreaming(boolean value) {
-        super.metadata.setIndex((byte) 16, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET + 1, Metadata.Boolean(value));
     }
 
     public boolean isStaring() {
-        return super.metadata.getIndex((byte) 17, false);
+        return super.metadata.getIndex(OFFSET + 2, false);
     }
 
     public void setStaring(boolean value) {
-        super.metadata.setIndex((byte) 17, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET + 2, Metadata.Boolean(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/monster/EndermiteMeta.java

@@ -5,6 +5,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class EndermiteMeta extends MonsterMeta {
+    public static final byte OFFSET = MonsterMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public EndermiteMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/monster/GiantMeta.java

@@ -5,6 +5,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class GiantMeta extends MonsterMeta {
+    public static final byte OFFSET = MonsterMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public GiantMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/monster/GuardianMeta.java

@@ -5,6 +5,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class GuardianMeta extends MonsterMeta {
+    public static final byte OFFSET = MonsterMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 2;
 
     private Entity target;
 
@@ -13,11 +15,11 @@ public class GuardianMeta extends MonsterMeta {
     }
 
     public boolean isRetractingSpikes() {
-        return super.metadata.getIndex((byte) 15, false);
+        return super.metadata.getIndex(OFFSET, false);
     }
 
     public void setRetractingSpikes(boolean retractingSpikes) {
-        super.metadata.setIndex((byte) 15, Metadata.Boolean(retractingSpikes));
+        super.metadata.setIndex(OFFSET, Metadata.Boolean(retractingSpikes));
     }
 
     public Entity getTarget() {
@@ -26,7 +28,7 @@ public class GuardianMeta extends MonsterMeta {
 
     public void setTarget(@NotNull Entity target) {
         this.target = target;
-        super.metadata.setIndex((byte) 16, Metadata.VarInt(target.getEntityId()));
+        super.metadata.setIndex(OFFSET + 1, Metadata.VarInt(target.getEntityId()));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/monster/MonsterMeta.java

@@ -3,9 +3,12 @@ package net.minestom.server.entity.metadata.monster;
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
 import net.minestom.server.entity.metadata.PathfinderMobMeta;
+import net.minestom.server.entity.metadata.minecart.AbstractMinecartMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class MonsterMeta extends PathfinderMobMeta {
+    public static final byte OFFSET = PathfinderMobMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     protected MonsterMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/monster/PiglinBruteMeta.java

@@ -5,6 +5,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class PiglinBruteMeta extends BasePiglinMeta {
+    public static final byte OFFSET = BasePiglinMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public PiglinBruteMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/monster/PiglinMeta.java

@@ -6,13 +6,15 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class PiglinMeta extends BasePiglinMeta {
+    public static final byte OFFSET = BasePiglinMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 3;
 
     public PiglinMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
     }
 
     public boolean isBaby() {
-        return super.metadata.getIndex((byte) 16, false);
+        return super.metadata.getIndex(OFFSET, false);
     }
 
     public void setBaby(boolean value) {
@@ -25,23 +27,23 @@ public class PiglinMeta extends BasePiglinMeta {
         } else {
             setBoundingBox(bb.getWidth() * 2, bb.getHeight() * 2);
         }
-        super.metadata.setIndex((byte) 16, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET, Metadata.Boolean(value));
     }
 
     public boolean isChargingCrossbow() {
-        return super.metadata.getIndex((byte) 17, false);
+        return super.metadata.getIndex(OFFSET + 1, false);
     }
 
     public void setChargingCrossbow(boolean value) {
-        super.metadata.setIndex((byte) 17, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET + 1, Metadata.Boolean(value));
     }
 
     public boolean isDancing() {
-        return super.metadata.getIndex((byte) 18, false);
+        return super.metadata.getIndex(OFFSET + 2, false);
     }
 
     public void setDancing(boolean value) {
-        super.metadata.setIndex((byte) 18, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET + 2, Metadata.Boolean(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/monster/SilverfishMeta.java

@@ -5,6 +5,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class SilverfishMeta extends MonsterMeta {
+    public static final byte OFFSET = MonsterMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public SilverfishMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/monster/SpiderMeta.java

@@ -5,8 +5,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class SpiderMeta extends MonsterMeta {
-
+    public static final byte OFFSET = MonsterMeta.MAX_OFFSET;
-    private final static byte MASK_INDEX = 15;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     private final static byte CLIMBING_BIT = 0x01;
 
@@ -15,11 +15,11 @@ public class SpiderMeta extends MonsterMeta {
     }
 
     public boolean isClimbing() {
-        return getMaskBit(MASK_INDEX, CLIMBING_BIT);
+        return getMaskBit(OFFSET, CLIMBING_BIT);
     }
 
     public void setClimbing(boolean value) {
-        setMaskBit(MASK_INDEX, CLIMBING_BIT, value);
+        setMaskBit(OFFSET, CLIMBING_BIT, value);
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/monster/VexMeta.java

@@ -5,8 +5,8 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class VexMeta extends MonsterMeta {
-
+    public static final byte OFFSET = MonsterMeta.MAX_OFFSET;
-    private final static byte MASK_INDEX = 15;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     private final static byte ATTACKING_BIT = 0x01;
 
@@ -15,11 +15,11 @@ public class VexMeta extends MonsterMeta {
     }
 
     public boolean isAttacking() {
-        return getMaskBit(MASK_INDEX, ATTACKING_BIT);
+        return getMaskBit(OFFSET, ATTACKING_BIT);
     }
 
     public void setAttacking(boolean value) {
-        setMaskBit(MASK_INDEX, ATTACKING_BIT, value);
+        setMaskBit(OFFSET, ATTACKING_BIT, value);
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/monster/WitherMeta.java

@@ -6,6 +6,8 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 
 public class WitherMeta extends MonsterMeta {
+    public static final byte OFFSET = MonsterMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 4;
 
     private Entity centerHead;
     private Entity leftHead;
@@ -22,7 +24,7 @@ public class WitherMeta extends MonsterMeta {
 
     public void setCenterHead(@Nullable Entity value) {
         this.centerHead = value;
-        super.metadata.setIndex((byte) 15, Metadata.VarInt(value == null ? 0 : value.getEntityId()));
+        super.metadata.setIndex(OFFSET, Metadata.VarInt(value == null ? 0 : value.getEntityId()));
     }
 
     @Nullable
@@ -32,7 +34,7 @@ public class WitherMeta extends MonsterMeta {
 
     public void setLeftHead(@Nullable Entity value) {
         this.leftHead = value;
-        super.metadata.setIndex((byte) 16, Metadata.VarInt(value == null ? 0 : value.getEntityId()));
+        super.metadata.setIndex(OFFSET + 1, Metadata.VarInt(value == null ? 0 : value.getEntityId()));
     }
 
     @Nullable
@@ -42,15 +44,15 @@ public class WitherMeta extends MonsterMeta {
 
     public void setRightHead(@Nullable Entity value) {
         this.rightHead = value;
-        super.metadata.setIndex((byte) 17, Metadata.VarInt(value == null ? 0 : value.getEntityId()));
+        super.metadata.setIndex(OFFSET + 2, Metadata.VarInt(value == null ? 0 : value.getEntityId()));
     }
 
     public int getInvulnerableTime() {
-        return super.metadata.getIndex((byte) 18, 0);
+        return super.metadata.getIndex(OFFSET + 3, 0);
     }
 
     public void setInvulnerableTime(int value) {
-        super.metadata.setIndex((byte) 18, Metadata.VarInt(value));
+        super.metadata.setIndex(OFFSET + 3, Metadata.VarInt(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/monster/ZoglinMeta.java

@@ -6,13 +6,15 @@ import net.minestom.server.entity.Metadata;
 import org.jetbrains.annotations.NotNull;
 
 public class ZoglinMeta extends MonsterMeta {
+    public static final byte OFFSET = MonsterMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     public ZoglinMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
     }
 
     public boolean isBaby() {
-        return super.metadata.getIndex((byte) 15, false);
+        return super.metadata.getIndex(OFFSET, false);
     }
 
     public void setBaby(boolean value) {
@@ -25,7 +27,7 @@ public class ZoglinMeta extends MonsterMeta {
         } else {
             setBoundingBox(bb.getWidth() * 2, bb.getHeight() * 2);
         }
-        super.metadata.setIndex((byte) 15, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET, Metadata.Boolean(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/monster/raider/AbstractIllagerMeta.java

@@ -2,9 +2,12 @@ package net.minestom.server.entity.metadata.monster.raider;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.monster.MonsterMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class AbstractIllagerMeta extends RaiderMeta {
+    public static final byte OFFSET = RaiderMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     protected AbstractIllagerMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/monster/raider/EvokerMeta.java

@@ -2,9 +2,12 @@ package net.minestom.server.entity.metadata.monster.raider;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.monster.MonsterMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class EvokerMeta extends SpellcasterIllagerMeta {
+    public static final byte OFFSET = SpellcasterIllagerMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public EvokerMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/monster/raider/IllusionerMeta.java

@@ -2,9 +2,12 @@ package net.minestom.server.entity.metadata.monster.raider;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.monster.MonsterMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class IllusionerMeta extends SpellcasterIllagerMeta {
+    public static final byte OFFSET = SpellcasterIllagerMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public IllusionerMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/monster/raider/PillagerMeta.java

@@ -2,9 +2,12 @@ package net.minestom.server.entity.metadata.monster.raider;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.monster.MonsterMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class PillagerMeta extends AbstractIllagerMeta {
+    public static final byte OFFSET = AbstractIllagerMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public PillagerMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/monster/raider/RaiderMeta.java

@@ -6,17 +6,19 @@ import net.minestom.server.entity.metadata.monster.MonsterMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class RaiderMeta extends MonsterMeta {
+    public static final byte OFFSET = MonsterMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     protected RaiderMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
     }
 
     public boolean isCelebrating() {
-        return super.metadata.getIndex((byte) 15, false);
+        return super.metadata.getIndex(OFFSET, false);
     }
 
     public void setCelebrating(boolean value) {
-        super.metadata.setIndex((byte) 15, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET, Metadata.Boolean(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/monster/raider/RavagerMeta.java

@@ -2,9 +2,12 @@ package net.minestom.server.entity.metadata.monster.raider;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.monster.MonsterMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class RavagerMeta extends RaiderMeta {
+    public static final byte OFFSET = RaiderMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public RavagerMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/monster/raider/SpellcasterIllagerMeta.java

@@ -2,9 +2,12 @@ package net.minestom.server.entity.metadata.monster.raider;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.monster.MonsterMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class SpellcasterIllagerMeta extends AbstractIllagerMeta {
+    public static final byte OFFSET = AbstractIllagerMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     protected SpellcasterIllagerMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
@@ -12,11 +15,11 @@ public class SpellcasterIllagerMeta extends AbstractIllagerMeta {
 
     @NotNull
     public Spell getSpell() {
-        return Spell.VALUES[super.metadata.getIndex((byte) 16, (byte) 0)];
+        return Spell.VALUES[super.metadata.getIndex(OFFSET, (byte) 0)];
     }
 
     public void setSpell(@NotNull Spell spell) {
-        super.metadata.setIndex((byte) 16, Metadata.Byte((byte) spell.ordinal()));
+        super.metadata.setIndex(OFFSET, Metadata.Byte((byte) spell.ordinal()));
     }
 
     public enum Spell {

src/main/java/net/minestom/server/entity/metadata/monster/raider/VindicatorMeta.java

@@ -2,9 +2,12 @@ package net.minestom.server.entity.metadata.monster.raider;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.monster.MonsterMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class VindicatorMeta extends AbstractIllagerMeta {
+    public static final byte OFFSET = AbstractIllagerMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public VindicatorMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/monster/raider/WitchMeta.java

@@ -2,20 +2,23 @@ package net.minestom.server.entity.metadata.monster.raider;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.monster.MonsterMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class WitchMeta extends RaiderMeta {
+    public static final byte OFFSET = RaiderMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 1;
 
     public WitchMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
     }
 
     public boolean isDrinkingPotion() {
-        return super.metadata.getIndex((byte) 16, false);
+        return super.metadata.getIndex(OFFSET, false);
     }
 
     public void setDrinkingPotion(boolean value) {
-        super.metadata.setIndex((byte) 16, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET, Metadata.Boolean(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/monster/skeleton/AbstractSkeletonMeta.java

@@ -6,6 +6,8 @@ import net.minestom.server.entity.metadata.monster.MonsterMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class AbstractSkeletonMeta extends MonsterMeta {
+    public static final byte OFFSET = MonsterMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     protected AbstractSkeletonMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/monster/skeleton/SkeletonMeta.java

@@ -2,9 +2,12 @@ package net.minestom.server.entity.metadata.monster.skeleton;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.monster.MonsterMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class SkeletonMeta extends AbstractSkeletonMeta {
+    public static final byte OFFSET = AbstractSkeletonMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public SkeletonMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/monster/skeleton/StrayMeta.java

@@ -2,9 +2,12 @@ package net.minestom.server.entity.metadata.monster.skeleton;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.monster.MonsterMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class StrayMeta extends AbstractSkeletonMeta {
+    public static final byte OFFSET = AbstractSkeletonMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public StrayMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/monster/skeleton/WitherSkeletonMeta.java

@@ -2,9 +2,12 @@ package net.minestom.server.entity.metadata.monster.skeleton;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.monster.MonsterMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class WitherSkeletonMeta extends AbstractSkeletonMeta {
+    public static final byte OFFSET = AbstractSkeletonMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public WitherSkeletonMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/monster/zombie/DrownedMeta.java

@@ -2,9 +2,12 @@ package net.minestom.server.entity.metadata.monster.zombie;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.monster.MonsterMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class DrownedMeta extends ZombieMeta {
+    public static final byte OFFSET = ZombieMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public DrownedMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/monster/zombie/HuskMeta.java

@@ -2,9 +2,12 @@ package net.minestom.server.entity.metadata.monster.zombie;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.monster.MonsterMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class HuskMeta extends ZombieMeta {
+    public static final byte OFFSET = ZombieMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 0;
 
     public HuskMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);

src/main/java/net/minestom/server/entity/metadata/monster/zombie/ZombieMeta.java

@@ -7,13 +7,15 @@ import net.minestom.server.entity.metadata.monster.MonsterMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class ZombieMeta extends MonsterMeta {
+    public static final byte OFFSET = MonsterMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 3;
 
     public ZombieMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
     }
 
     public boolean isBaby() {
-        return super.metadata.getIndex((byte) 15, false);
+        return super.metadata.getIndex(OFFSET, false);
     }
 
     public void setBaby(boolean value) {
@@ -26,15 +28,15 @@ public class ZombieMeta extends MonsterMeta {
         } else {
             setBoundingBox(bb.getWidth() * 2, bb.getHeight() * 2);
         }
-        super.metadata.setIndex((byte) 15, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET, Metadata.Boolean(value));
     }
 
     public boolean isBecomingDrowned() {
-        return super.metadata.getIndex((byte) 17, false);
+        return super.metadata.getIndex(OFFSET + 2, false);
     }
 
     public void setBecomingDrowned(boolean value) {
-        super.metadata.setIndex((byte) 17, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET + 2, Metadata.Boolean(value));
     }
 
 }

src/main/java/net/minestom/server/entity/metadata/monster/zombie/ZombieVillagerMeta.java

@@ -2,25 +2,28 @@ package net.minestom.server.entity.metadata.monster.zombie;
 
 import net.minestom.server.entity.Entity;
 import net.minestom.server.entity.Metadata;
+import net.minestom.server.entity.metadata.monster.MonsterMeta;
 import net.minestom.server.entity.metadata.villager.VillagerMeta;
 import org.jetbrains.annotations.NotNull;
 
 public class ZombieVillagerMeta extends ZombieMeta {
+    public static final byte OFFSET = ZombieMeta.MAX_OFFSET;
+    public static final byte MAX_OFFSET = OFFSET + 2;
 
     public ZombieVillagerMeta(@NotNull Entity entity, @NotNull Metadata metadata) {
         super(entity, metadata);
     }
 
     public boolean isConverting() {
-        return super.metadata.getIndex((byte) 18, false);
+        return super.metadata.getIndex(OFFSET, false);
     }
 
     public void setConverting(boolean value) {
-        super.metadata.setIndex((byte) 18, Metadata.Boolean(value));
+        super.metadata.setIndex(OFFSET, Metadata.Boolean(value));
     }
 
     public VillagerMeta.VillagerData getVillagerData() {
-        int[] data = super.metadata.getIndex((byte) 17, null);
+        int[] data = super.metadata.getIndex(OFFSET + 1, null);
         if (data == null) {
             return new VillagerMeta.VillagerData(VillagerMeta.Type.PLAINS, VillagerMeta.Profession.NONE, VillagerMeta.Level.NOVICE);
         }
@@ -28,7 +31,7 @@ public class ZombieVillagerMeta extends ZombieMeta {
     }
 
     public void setVillagerData(VillagerMeta.VillagerData data) {
-        super.metadata.setIndex((byte) 17, Metadata.VillagerData(
+        super.metadata.setIndex(OFFSET + 1, Metadata.VillagerData(
                 data.getType().ordinal(),
                 data.getProfession().ordinal(),
                 data.getLevel().ordinal() + 1