"Full Moon" (満月 Mangetsu, lit. "The Full Moon") is the twenty-first chapter of the Dragon Ball manga.
The chapter opens with the gang trying to find a way out of the death trap, but to no avail. As Emperor Pilaf and his henchmen await morning, Puar notices the full moon. At the mention of a full moon, Goku tells the story of how a monster appears on nights of the full moon, and that his Grandpa Gohan was crushed by the monster (it was really Goku himself, but he has no recollection of the event). As he tells his story, the gang begins to realize it was Goku who crushed his grandfather. Just as they tell him not to look at the full moon, he does so, but nothing happens. As the gang takes a sigh of relief, the transformation sets in, causing Goku to turn into a giant ape, causing Pilaf and his henchmen to wake up. Just then, Goku breaks through the roof of the castle.