Goku is exposed to a full moon and transformed into a huge, allen gorilla and goes on a rampage, attacking friends and foes alike. Bulma, Yamcha and Puar must try and return Goku to his normal self without hurting him and avoid Pilaf's army while they're doing it. As they successfully "save" Goku, they discover that his "curse" is really the key to his myterious origin.