Piccolo

Piccolo is the son/reincarnation of Piccolo Daimaō, and was spawned to avenge his sire's death at the hands of Son Goku. Later on, he abandoned his ambitions to rule earth and joined Goku and company as an ally and a friend. He seems to also share a deep bond with Goku's son, Gohan, and appears to be a sort of second father to him. Piccolo eventually learned that he was actually a alien from the planet Namek, and not a demon.

Goin' Green
Piccolo defeated Mac Gargan in the opening round, but then tied with GIR in round 2, eliminating them both from the tournament.