Crabbe is large, with gorilla-like arms, and has a pudding bowl style haircut. He is very mean, and very stupid, rendering him little more than just a 'follower' of Malfoy and seems inept at trying to do things his own way.
He seems unable to be able to make up his own mind, and see things his own way and is always being told what to do and it is pretty sad.
His father Crabbe Sr. is a Death Eater and is also a dim fellow as well.