Mob AI bug, randomly just stands still, knocking up instead of back.

import net.minecraft.block.Block;

import net.minecraft.entity.Entity;

import net.minecraft.entity.EntityLiving;

import net.minecraft.entity.SharedMonsterAttributes;

import net.minecraft.entity.ai.EntityAIAttackOnCollide;

import net.minecraft.entity.ai.EntityAIHurtByTarget;

import net.minecraft.entity.ai.EntityAILookIdle;

import net.minecraft.entity.ai.EntityAIMoveThroughVillage;

import net.minecraft.entity.ai.EntityAIMoveTowardsRestriction;

import net.minecraft.entity.ai.EntityAINearestAttackableTarget;

import net.minecraft.entity.ai.EntityAISwimming;

import net.minecraft.entity.ai.EntityAIWander;

import net.minecraft.entity.ai.EntityAIWatchClosest;

import net.minecraft.entity.monster.EntityMob;

import net.minecraft.entity.passive.EntityVillager;

import net.minecraft.entity.player.EntityPlayer;

import net.minecraft.potion.Potion;

import net.minecraft.potion.PotionEffect;

import net.minecraft.world.World;

public class EntityCharger extends EntityMob {

public EntityCharger(World par1World) {

super(par1World);

this.tasks.addTask(0, new EntityAISwimming(this));

        this.tasks.addTask(2, new EntityAIAttackOnCollide(this, EntityPlayer.class, 1.0D, false));

        this.tasks.addTask(4, new EntityAIAttackOnCollide(this, EntityVillager.class, 1.0D, true));

        this.tasks.addTask(5, new EntityAIMoveTowardsRestriction(this, 1.0D));

        this.tasks.addTask(6, new EntityAIMoveThroughVillage(this, 1.0D, false));

        this.tasks.addTask(7, new EntityAIWander(this, 1.0D));

        this.tasks.addTask(8, new EntityAIWatchClosest(this, EntityPlayer.class, 8.0F));

        this.tasks.addTask(8, new EntityAILookIdle(this));

        this.targetTasks.addTask(1, new EntityAIHurtByTarget(this, true));

        this.targetTasks.addTask(2, new EntityAINearestAttackableTarget(this, EntityPlayer.class, 0, true));

        this.targetTasks.addTask(2, new EntityAINearestAttackableTarget(this, EntityVillager.class, 0, false));

        this.setSize(1.0F, 1.3F);

// TODO Auto-generated constructor stub

}

protected String getLivingSound(){

return "mob.wither.idle";

}

protected String getDeathSound(){

return "mob.wither.death";

}

protected String getHurtSound(){

    return "mob.wither.hurt";

}

protected void func_145780_a(int p_145780_1_, int p_145780_2_, int p_145780_3_, Block p_145780_4_)

    {

        this.playSound("mob.pig.step", 0.15F, 1.0F);

    }

protected Entity findPlayerToAttack(){

EntityPlayer entityPlayer = this.worldObj.getClosestVulnerablePlayerToEntity(this, 32.0D);

return entityPlayer != null && this.canEntityBeSeen(entityPlayer) ? entityPlayer : null;

}

public void applyEntityAttributes(){

super.applyEntityAttributes();

this.getEntityAttribute(SharedMonsterAttributes.attackDamage).setBaseValue(5.0D);

this.getEntityAttribute(SharedMonsterAttributes.followRange).setBaseValue(32.0D);

this.getEntityAttribute(SharedMonsterAttributes.knockbackResistance).setBaseValue(0.5D);

this.getEntityAttribute(SharedMonsterAttributes.movementSpeed).setBaseValue(0.44D);

this.getEntityAttribute(SharedMonsterAttributes.maxHealth).setBaseValue(35.0D);

}

protected void entityInit()

    {

        super.entityInit();

        this.getDataWatcher().addObject(12, Byte.valueOf((byte)0));

        this.getDataWatcher().addObject(13, Byte.valueOf((byte)0));

        this.getDataWatcher().addObject(14, Byte.valueOf((byte)0));

    }

@Override

public boolean attackEntityAsMob(Entity par1Entity) {

        super.attackEntityAsMob(par1Entity);

        if (this.entityToAttack != null) {

            this.entityToAttack.addVelocity(this.motionX * 2.0D, 2.0D, this.motionZ * 2.00D);

            if(this.entityToAttack instanceof EntityLiving) {

                ((EntityLiving)this.entityToAttack).addPotionEffect(new PotionEffect(Potion.moveSlowdown.id, 50, 0));

            }

            return true;

        }

        return false;

    }

@Override

protected boolean isAIEnabled() {

        return true;

    }

}