I have no idea if I'm doing this even near right but when I spawn a chicken next to a zombie I get this error "Can't find attribute minecraft:generic.attack_damage" error.

package me.prouddesk.proudmod.proudmod.common.events;

import me.prouddesk.proudmod.proudmod.ProudMod;
import net.minecraft.entity.Entity;
import net.minecraft.entity.EntityType;
import net.minecraft.entity.ai.attributes.Attributes;
import net.minecraft.entity.ai.goal.*;
import net.minecraft.entity.monster.ZombieEntity;
import net.minecraft.entity.passive.ChickenEntity;
import net.minecraftforge.event.entity.EntityAttributeModificationEvent;
import net.minecraftforge.event.entity.EntityJoinWorldEvent;
import net.minecraftforge.eventbus.api.SubscribeEvent;
import net.minecraftforge.fml.common.Mod;


@Mod.EventBusSubscriber(modid = ProudMod.MODID)
public class PlayerEvents {

    @SubscribeEvent
    public static void onEntitySpawn(EntityJoinWorldEvent e)
    {
        Entity mob = e.getEntity();
        if(mob instanceof ChickenEntity) {
            ChickenEntity chick = (ChickenEntity) mob;

            chick.goalSelector.addGoal(2, new MeleeAttackGoal(chick, 1.0D, false));
            chick.targetSelector.addGoal(2, new NearestAttackableTargetGoal<>(chick, ZombieEntity.class, true));
        }
    }

    @SubscribeEvent
    public static void Attributes(EntityAttributeModificationEvent e) {
        e.add(EntityType.CHICKEN, Attributes.ATTACK_DAMAGE, 2.0D);
    }
}

Edited June 21, 20214 yr by ProudDesk

You need to register your Attributes void to the Mod Eventbus.

6 hours ago, DietmarKracht said:

You need to register your Attributes void to the Mod Eventbus.

How would I do that?  I tried to register the whole class by doing 

MinecraftForge.EVENT_BUS.register(ChickenAttack.class);

But that doesn't work.

11 minutes ago, ProudDesk said:

How would I do that?  I tried to register the whole class by doing 

But that doesn't work.

use the automatic event registry
https://mcforge.readthedocs.io/en/latest/events/intro/#automatically-registering-static-event-handlers

13 minutes ago, Luis_ST said:

use the automatic event registry
https://mcforge.readthedocs.io/en/latest/events/intro/#automatically-registering-static-event-handlers

I am already registering them automatically and I don't really see any difference between that link and my class.

23 minutes ago, diesieben07 said:

You are registering to the forge event bus, the event fires on the mod event bus.

Ahh! Thank you, I fixed it.