Meatball

This boss will often spawn purple orbs, which will increase your damage done when picked up (just walk on them), stacking infinitely. After some time, Meatball will enrage.
The key is to know when you should stop collecting orbs and burst all your cooldowns in an attempt to kill the boss. If you have enough dps, I'm pretty sure you will succeed sooner or later :)

Ashamed to say i died to this guy my first attempt, I was so cocky after i downed battletron i decided to try this guy blind, genius i am immediately assumed the orbs were to be avoided and died in ten seconds.....

orbs good.

For anyone who is having trouble with meatball here a tip that no one else seemed to mention.

He drops the little orbs only as fast as you hit him. Meaning if you have a fast ticking dot or a fast hitting instant cast spell the faster he will produce the orbs to pick up. So do as many hits as you can as fast as you can to him.

This guy will definitely be easier for dot classes as each dot provides a hit to him.

I was able to beat him as a Mage by speccing into nether tempest and going in as frost spec.
Cast nether tempest, mirror images and frost orb and you have tons of small hits on him that each produce an orb.

Then all you need to do is concentrate on collecting them which will be much easier and much faster.
Wait till about 30-40 stacks and nuke. Easy once you know how.