So, I've tried to make my mob tameable, able to sit/wait and so on. I've looked at the wolf and ocelot code, but I couldn't figure out how to make it tameable there (could've been looking at wrong place however...) but here's the code now... quite bad but yeah... it isn't that easy to make a mob. But it would be nice with some help. 

package com.holmisas.entity;

import net.minecraft.entity.EntityAgeable;
import net.minecraft.entity.SharedMonsterAttributes;
import net.minecraft.entity.ai.EntityAIFollowOwner;
import net.minecraft.entity.ai.EntityAILookIdle;
import net.minecraft.entity.ai.EntityAISwimming;
import net.minecraft.entity.ai.EntityAITempt;
import net.minecraft.entity.ai.EntityAIWander;
import net.minecraft.entity.ai.EntityAIWatchClosest;
import net.minecraft.entity.monster.EntityMob;
import net.minecraft.entity.passive.EntityAnimal;
import net.minecraft.entity.passive.EntityTameable;
import net.minecraft.entity.player.EntityPlayer;
import net.minecraft.init.Items;
import net.minecraft.item.Item;
import net.minecraft.item.ItemFood;
import net.minecraft.item.ItemStack;
import net.minecraft.world.World;

public class EntityMiniDude extends EntityTameable {

public EntityMiniDude(World par1World) {
	super(par1World);
	this.setSize(1.0F, 1.0F);
	this.tasks.addTask(0, new EntityAIWander(this, 1.0D));
	this.tasks.addTask(1, new EntityAILookIdle(this));
	this.tasks.addTask(2, new EntityAISwimming(this));
	this.tasks.addTask(3, new EntityAITempt(this, 1.7D, Items.sugar, false));
	this.tasks.addTask(4, new EntityAIWatchClosest(this, EntityPlayer.class, 8.0F));


}

public boolean isAIEnabled(){
	return true;
}

protected void applyEntityAttributes(){
	super.applyEntityAttributes();
	this.getEntityAttribute(SharedMonsterAttributes.maxHealth).setBaseValue(40.0D);
	this.getEntityAttribute(SharedMonsterAttributes.movementSpeed).setBaseValue(0.3D);

}
/**
 * Random Drop Between 1 - 3 dropped at a time
 */
protected Item getDropItem(){
	return Items.apple;
}

  public int getMaxSpawnedInChunk(){
        return 8;
    }
   
@Override
public EntityAgeable createChild(EntityAgeable var1) {
	return new EntityMiniDude(worldObj);
}

}

Keep in mind this is no way perfect...but here's what I did so far (it makes them tameable, but that's the extent of it. I haven't gotten anything else beyond sitting)

 

Under your public EntityMiniDude code (where you have your AI programming), you want to add:

this.setTamed(false);

If you want it's HP to change when it's tamed, you need:

protected void applyEntityAttributes()
    {
        super.applyEntityAttributes();
        this.getEntityAttribute(SharedMonsterAttributes.movementSpeed).setBaseValue(0.3D);
        if (this.isTamed()) {
            this.getEntityAttribute(SharedMonsterAttributes.maxHealth).setBaseValue(100.0D); //The value after it's tamed.
        }
        else {
            this.getEntityAttribute(SharedMonsterAttributes.maxHealth).setBaseValue(8.0D); //The value before it's tamed.
        }
    }

 

It also seems like you need this, but I'm not 100% sure (seems like that previous code would handle this, but I dunno):

public void setTamed(boolean par1)
    {
        super.setTamed(par1);

        if (par1)
        {
            this.getEntityAttribute(SharedMonsterAttributes.maxHealth).setBaseValue(100.0D);
        }
        else
        {
            this.getEntityAttribute(SharedMonsterAttributes.maxHealth).setBaseValue(8.0D);
        }
    }

 

After that...this is where I got lost and can't figure out anything else...You need this set of code, but I have no idea how any of it works or what it does...maybe someone else could help?

 protected void updateAITick()
    {
        this.dataWatcher.updateObject(18, Float.valueOf(this.getHealth()));
    }

    protected void entityInit()
    {
        super.entityInit();
        this.dataWatcher.addObject(18, new Float(this.getHealth()));
        this.dataWatcher.addObject(19, new Byte((byte)0));
        this.dataWatcher.addObject(20, new Byte((byte)BlockColored.func_150032_b(1)));
    }

The above code has something to do with it checking health and healing, but it doesn't seem to work besides preventing a crash with the following code (which, again, I don't understand):

 public boolean interact(EntityPlayer par1EntityPlayer)
    {
    	ItemStack itemstack = par1EntityPlayer.inventory.getCurrentItem();

        if (this.isTamed())
        {
            if (itemstack != null)
            {
                if (itemstack.getItem() instanceof ItemFood)
                {
                    ItemFood itemfood = (ItemFood)itemstack.getItem();

                    if (itemfood.isWolfsFavoriteMeat() && this.dataWatcher.getWatchableObjectFloat(18) < 20.0F)
                    {
                        if (!par1EntityPlayer.capabilities.isCreativeMode)
                        {
                            --itemstack.stackSize;
                        }

                        this.heal((float)itemfood.func_150905_g(itemstack));

                        if (itemstack.stackSize <= 0)
                        {
                            par1EntityPlayer.inventory.setInventorySlotContents(par1EntityPlayer.inventory.currentItem, (ItemStack)null);
                        }

                        return true;
                    }
                }
            }

            if (par1EntityPlayer.getCommandSenderName().equalsIgnoreCase(this.getOwnerName()) && !this.worldObj.isRemote && !this.isBreedingItem(itemstack))
            {
                this.aiSit.setSitting(!this.isSitting());
                System.out.println("sit");
                this.isJumping = false;
                this.setPathToEntity((PathEntity)null);
                this.setTarget((Entity)null);
                this.setAttackTarget((EntityLivingBase)null);
            }
        }
        else if (itemstack != null && itemstack.getItem() == Items.apple)
        {
            if (!par1EntityPlayer.capabilities.isCreativeMode)
            {
                --itemstack.stackSize;
            }

            if (itemstack.stackSize <= 0)
            {
                par1EntityPlayer.inventory.setInventorySlotContents(par1EntityPlayer.inventory.currentItem, (ItemStack)null);
            }

            if (!this.worldObj.isRemote)
            {
                if (this.rand.nextInt(3) == 0)
                {
                    this.setTamed(true);
                    this.setPathToEntity((PathEntity)null);
                    this.setAttackTarget((EntityLivingBase)null);
                    this.aiSit.setSitting(true);
                    this.setHealth(100.0F);
                    this.setOwner(par1EntityPlayer.getCommandSenderName());
                    this.playTameEffect(true);
                    this.worldObj.setEntityState(this, (byte)7);
                }
                else
                {
                    this.playTameEffect(false);
                    this.worldObj.setEntityState(this, (byte)6);
                }
            }

            return true;
        }

        return super.interact(par1EntityPlayer);
    }

Thanks! It works pretty well, the only problem is that when I right click a tamed minidude the game crash, and aslo when I start the game again it seems like the mob isn't tamed anymore otherwise it's good

If you're starting the game through Eclipse, you will have a different player name, but the mob will still belong to the name you had when you tamed it.