Now or when he was fighting? Because if you mean when he was fighting, it might just be his stance making him look like that.
He did when you think about it. He had round, almost shell-like back and spindly limbs. Always thought Tommy Hearns looked more like a praying mantis than a cobra, and that Bob Foster looked like a centipede.
He fought kinda hunched over, forward leaning but this is also what made him one of the best fighters at parrying shots with his gloves, it was more of a turtle shell defense; neck down, shoulders up etc. He really didn't give much of a target; shoulders, forearms, gloves etc.....