Added the SpecialMobDropHelper.

src/main/java/turniplabs/halplibe/helper/SpecialMobDropHelper.java

@@ -0,0 +1,23 @@
+package turniplabs.halplibe.helper;
+
+import net.minecraft.core.WeightedRandomBag;
+import net.minecraft.core.WeightedRandomLootObject;
+
+public class SpecialMobDropHelper {
+
+    /**
+     * Manipulates the loot that can drop when a creeper is killed by a skeleton.
+     */
+    public static class Creeper {
+        private static final WeightedRandomBag<WeightedRandomLootObject> creeperDrops = new WeightedRandomBag<>();
+
+        public static void addDrop(WeightedRandomLootObject drop, int weight) {
+            creeperDrops.addEntry(drop,weight);
+        }
+
+        public static WeightedRandomBag<WeightedRandomLootObject> getDrops() {
+            return creeperDrops;
+        }
+    }
+
+}

src/main/java/turniplabs/halplibe/mixin/MobCreeperMixin.java

@@ -0,0 +1,33 @@
+package turniplabs.halplibe.mixin;
+
+import net.minecraft.core.WeightedRandomLootObject;
+import net.minecraft.core.entity.Entity;
+import net.minecraft.core.entity.monster.MobCreeper;
+import net.minecraft.core.entity.monster.MobMonster;
+import net.minecraft.core.item.ItemStack;
+import net.minecraft.core.world.World;
+import org.jetbrains.annotations.Nullable;
+import org.spongepowered.asm.mixin.Intrinsic;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfo;
+import turniplabs.halplibe.helper.SpecialMobDropHelper;
+
+@Mixin(value = MobCreeper.class,remap = false)
+public abstract class MobCreeperMixin extends MobMonster {
+
+    private MobCreeperMixin(@Nullable World world) {
+        super(world);
+    }
+
+    @Inject(method = "onDeath", at = @At(value = "INVOKE", target = "Lnet/minecraft/core/entity/monster/MobCreeper;dropItem(II)Lnet/minecraft/core/entity/EntityItem;",shift = At.Shift.AFTER))
+    public void dropItemsOnDeath(Entity entityKilledBy, CallbackInfo ci) {
+        for (WeightedRandomLootObject entry : SpecialMobDropHelper.Creeper.getDrops().getEntries()) {
+            ItemStack stack = entry.getItemStack();
+            if(stack != null){
+                dropItem(stack,0.0f);
+            }
+        }
+    }
+}

src/main/resources/halplibe.mixins.json

@@ -7,6 +7,7 @@
     "I18nMixin",
     "MinecraftMixin",
     "MinecraftServerMixin",
+    "MobCreeperMixin",
     "accessors.BlockAccessor",
     "accessors.BlocksAccessor",
     "accessors.EntityFireflyFXAccessor",