From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
Gregory was very respectful of North Kaio and always spoke highly of him, but would talk trash to anyone he did not believe was better than him. North Kaio showed up after Son Goku managed to catch Bubbles. North Kaio gave Goku the new task of hitting Gregory with a heavy hammer. Much later, Gregory was killed when Semi-Perfect Cell blew up on North Kaio's World. Although Gregory did not appear in the manga by Akira Toriyama, he was one of the many filler characters designed in Dragon Ball Z: Son Gokū Densetsu by Akira Toriyama and his staff.
Gregory appeared in Dragon Ball Z: The Tree of Might.
- Japanese dub: Yūji Mitsuya (Dragon Ball Z); Yūsuke Numata (Dragon Ball Kai)
- Ocean Group dub: Doug Parker
- FUNimation dub: John Burgmeier