Dragon Ball Shenron Star Mask

Shenron is said to live in the fiery center of the Earth, whenever he is called he will arrive to grant one wish before returning to his fiery home to sleep until he is called again. Before the events of Dragon Ball, the last time Shenron was summoned was to grant someone's wish to become king (possibly referring to King Furry or one of his ancestors) as Bulma explains to Goku in their first meeting.