Dragon Ball Episode 13: The Legend of Goku
Episode 13 of 153 of Dragon Ball, aired May 21, 1986, 25 minutes. Available with English subtitles and dub where released.
Episode summary
Goku is exposed to a full moon. Transforming into a huge, alien gorilla, Goku goes on a rampage, attacking friends and foes alike. Can Bulma, Yamcha, and Puar return Goku to his normal self without hurting him and while also avoiding Emperor Pilaf's army?