From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
Smitty is a criminal.
Smitty appeared during the Majin Buu Saga. He hung around with the madman Van Zant. In the uncut version, a scene was shown where Van Zant got Smitty to shoot an old man. Smitty hesitated to kill him at first. After he did kill him, he found it fun to kill people. After he killed many more innocent people, they attacked Fat Boo and blew up his house. Mister Satan then beat them up and knocked Smitty off the edge of the hill before he pummeled Van Zant.
Smitty watched the battle between Mister Boo and Evil Boo, his tall thin gray counterpart. When Evil Boo ate Mister Boo and turned into Super Boo, he noticed Smitty, who desperately tried to run. Super Boo turned into liquid, went down Smitty's throat, and made him expand until he exploded. Most of the details of this scene were cut from the edited version including a scene in the uncut version where Smitty shoots Fat Boo, making several holes in him which healed up.
Dragon Ball GT
Smitty appeared in Dragon Ball Z: Buu's Fury.
- Smitty has a Scottish accent in the Ocean Group dub.