Just a thought, wouldn't Mr. Terrible also be out of shape? The point of Mr. Terrific is that he's both a mental and physical specimen so, it would seem that his polar opposite would not only be an 'engine of chaos' but also kind of chubby. As an overweigh

I had him as gangly and smelly and a bit of a disastrous slob, that’s how Dale Eaglesham drew him. Nicola prettied him up a little bit!