I always thought "Casket Dave" would make a good CASS name. No particular reason why, as my name is Tim, but I just thought it was cool for whatever reason. I am a much bigger dude than you are, and if it were me, I would just likely just add "Fats" to something and be done with it. We are big men! No sense hiding it! Other suggestions:
Pickle Barrel Pete.
Big Medicine.
Eclipse Roberts. See, this one is sublime in that it plays a couple of different ways. One is that your big and blot out the sun, and when the sun goes, it turns black. You wear black. Genius.
My roommate just walked in and reminded me that "tons of fun" would be good. He is a jerk. Stand by while I deliver a punch to his solar-plexus....
Allright. Moving on:
Long Lost Ed. I don't know what that means, but it sounds cool.
Frying Pan McAlister.
Biscuits Callahan.
Listen, I have a million of them. Feel free to take anyone that you want.
Dangit, I just noticed "Jack Anvil".... Thats pretty good. It's no "Pickle Barrel Pete", but still pretty good...