Thumbskull

Thumbskull is a minor villain and recurring character in Cartoon Network's Ben 10 animated franchise.

Description
A hulking brute of a man whose skin is a deathly pallor, Thumbskull has a giant fingernail on his forehead, hence his name. He is possessed of a degree of superhuman strength; in some incarnations, this is sufficient to allow him to fight toe-to-toe in close combat with Four Arms, the strongest of Ben Tennyson's alien modes.

Along with Acid Breath and Frightwig, Thumbskull forms the Circus Freak Trio, a gang of mutant henchman who work for crazed circus clown Zombozo. Within the group, Thumbskull functions as the muscle, as he is not overly gifted with intelligence.