Goku's Ancestors (よみがえるサイヤ人伝説! 悟空のルーツ, Yomigaeru Saiya-jin Densetsu! Goku no Rutsu) is the twentieth episode of the Vegeta Saga in the uncut Dragon Ball Z series. The episode first aired on September 20, 1989. Its original American air date was July 12, 2005.
He also relates to Goku how the Saiyans, who had wiped out the only other humanoid race on Planet Vegeta (called the Tuffles), had risen to acts of interstellar terror, clearing entire planets for resale to other races. They had since been driven to near extinction, and only four individuals survived the destruction of Vegeta.
When Goku learns of the evil heritage of the Saiyans, he flies off in a burst of light towards Gregory, focused only on hammering him. Two weeks later, he succeeds. Back on Earth, Krillin and the others complete their training at Kami's Lookout.
- The events in this episode (including Gregory's existence) do not appear in the manga, and are mostly filler for the anime. Despite this, Gregory also appears in Dragon Ball Kai.
- The part of the story stating that the Kami of planet Vegeta destroyed it would later be contradicted when it is later revealed that Frieza destroyed the Saiyan homeworld. However, the episode Explosion of Anger does briefly allude to the Kami of planet Vegeta's role in the destruction of the Saiyan race when Goku tells Frieza "They [the Saiyans] paid for their mistakes!"
- Goku is shown wearing a Battle Armor in this episode.
- King Kai says that there is 70 days left before the arrival of the Saiyans, but in the previous episode he said that there was 88 days and it took Goku three weeks (or 21 days; according to the summary) to catch Bubbles and two weeks (or 14 days) to hit Gregory. 21 + 14 = 35. 88 - 35 = 53; there are 53 days left, not 70.