He was a giant of a man, standing at over 6'7" and typically weighing over 500 pounds, typically convincing his foes that his girth was fat.
It most certainly wasn't. That's all muscle, and and was shown to be capable of crushing skulls, ribs, and spines with ease. Hand to hand combat with him was often tantamount to suicide.
He was a genius, self-taught in the ways of the world, and while he usually appeared to be a legitimate business man in his home Universes, he almost always wasn't, with some kind of criminal activity operating in the background of his business empire.