King Kai

King Kai (界王, Kaiō; lit. "King of the Worlds"), or North Kai (北の界王, Kita no Kaiō; lit. "North Kaio" or "North King of the Worlds"), is a supporting protagonist in the Dragon Ball manga and the animes Dragon Ball Z and Dragon Ball GT. He is a deity, the ruler of the North Galaxy, and Goku's final martial arts teacher, and later mentor. He also taught Yamcha, Tien Shinhan, Piccolo and Chiaotzu.