Zombozo is one of Ben's first enemies. He is a cruel and creepy clown mastermind with some similarities to the Joker from Batman. Zombozo was mostly hard to defeat for Ben because he was afraid of clowns. Ben managed to conquer this fear however, and defeat Zombozo.
Despite being a minor villain in the original show, Zombozo played a key role by introducing the Circus Freak Trio, who later became recurring villains.