Mr. Popo is an immortal djinn who lives with Kami in Kami's Lookout and is bound there eternally as the gardener and caretaker. He has served every other Kami (God/Guardian) of the Earth since the beginning of time. He was trained by the recent Kami himself and trained Goku for 3 years in order to fight Piccolo.

Mr. Popo is an excellent martial arts master. When he is introduced in Dragon Ball, his fighting prowess is far superior to Goku's in nearly all respects, when the two meet at the Lookout.

Mr. Popo and Kami train Krillin, Tien Shinhan, Yamcha, Chiaotzu and Yajirobe in order to help combat the approaching threat of the Saiyans, through many different training methods, including the Pendulum Room, intending to show the full power even the lower class Saiyans used to possess. Mr. Popo and Kami come to the realization that Piccolo has become far less evil than he was five years ago, when they notice that Raditz's soul, who was killed by Piccolo, did not become lost like other souls killed by demons.