Thumbskull (Classic)

"Thumbskull" is a minor recurring villain who first appeared in Last Laugh as a henchmen working under Zombozo, he then appeared in Ghostfreaked Out" when the Circus Freak Trio went solo and they were forced to work under Ghostfreak until his defeat, and then in Ben 10 vs. The Negative 10. Thumbskull, as the name suggests, has a head shaped like a thumb. Instead of hair Thumbskull had a horn which was broken previous to his on screen appearance. He also has incredible strength (though inferior to that of Four Arms), but limited intelligence, normally serving as the 'brawn' of the group. He was also easily beaten by Ben, normally even worse than the others. His name is a play on the insult "numbskull," as well as the obvious appearance gag.

Powers and Abilities
Has incredible super-strength, but not as much as Four Arms. He doesn't appear to any other powers than brute strength.