Monkey-ken
From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
Directory: Techniques → Physical techniques → Martial arts → Rush attacks
The Monkey-ken (猿拳, Saru-ken; Literally meaning "Monkey Fist") is a rush attack used by Son Goku. Goku confuses his opponent by pretending to be a crazy Monkey.
History
Goku used this attack in his match against Jackie Chun at the 21st Tenkaichi Tournament. After Jackie Chun used the Sui-ken, Goku countered with the Crazy Fist and Monkey-ken.
Manga
Goku used the Crazy Fist and the Monkey-ken one after the other.
Anime
Goku only used the Monkey-ken.