This is a sweet animation, but I think it needs some more polish. First of all I think you should tone down or clean up some of that sub-pixel movement, unless you're going for a mutant made out of jelly, that is.

Other then that, some more animation and secondary-motions all around. I made a quick edit to illustrate some stuff.

Just changed the colors a bit, slided some stuff around, added eyes and drool (that's a must if you're going for something like Paul Robertson), etc.
I think that a circular idle-motion would be more interesting and menacing too look at, then just a "back and forth" motion.
There's a lot more that could be done with this. Liquid squishing around inside those things on his back, his belly inflating and deflating?
I'd love to see you push this further!