From Dragon Ball Encyclopedia, the ''Dragon Ball'' wiki
Popo used a magic carpet for transportation. Though he did not appear to physically age, Popo was very old. He had served Kami, the guardian of Planet Earth, for hundreds of years. He had served Kami's predecessor as well as every other guardians of Planet Earth in the past. Being the loyal and faithful servant that he is, his purpose consists mainly of tending to the Heavenly Realm, keeping the place clean, helping to reconstruct Shen Long if needed, and most importantly taking care of Kami. He also tends to the ancient butterfly garden that he planted thousands of years ago, and enjoys the more simple things in life. While FUNimation's English dubbed Popo speaks complete, highly sophisticated sentences, the Japanese version proves him to be a seemingly primitive figure. His grasp of the common tongue is less than the English-dubbed version makes it out to be, and in addition, the Japanese version has him commonly referring to himself in the third person, which is done in the English version too as well as in the video game Dragon Ball Z: Budokai Tenkaichi.
Although his skill as a martial artist is not shown frequently, Popo was an excellent martial arts master. When he was introduced in Dragon Ball, he was far stronger than Son Goku when the two met and devoured Goku's Kamehameha resulting in a smoky belch. He trained Goku for three years until the young warrior learned everything he knew and entered the 23rd Tenkaichi Tournament to defeat Piccolo with his newly attained abilities. Some of the techniques Goku developed in his three-year training later proved valuable, such as the Super Kamehameha – a more lethal version of the trademark attack. When used against Piccolo at the Tenkaichi Tournament, however, the Demon survived it with minimal damage.
Dragon Ball Z
Five years later, Mr. Popo and Kami train Kuririn, Tenshinhan, Yamcha, Chaozu and Yajirobe in order to help combat the approaching threat of the Saiyans. He also helps Bulma, Kuririn, and Son Gohan get to Planet Namek by showing Bulma the location of Kami's old spaceship. He later collects the Dragon Balls in less than one day on Earth to resurrect all those who were killed by Frieza and his soldiers on Planet Namek.
Garlic Jr.'s return
In the filler Garlic Jr. Saga, Popo was attacked by Garlic Jr.'s henchmen while watering the plants on the Lookout. He is sealed in a glass cup by Garlic Jr. Later, he is released by Kuririn and Piccolo. He takes Kami to the bottom of the Lookout to spread the Sacred Water where the former Guardians' graves lie. He later spreads the Sacred Water to the Earth.
The Androids and Cell
Three years later, Popo appeared again in the Imperfect Cell Saga where he led Goku, Gohan, Trunks, and Vegeta to the Room of Spirit and Time for a year of training in one day. Later, he observed the Cell Games from the Heavenly Realm with the new Kami of Planet Earth, Dende.
Death and revival
Seven years later, in the Majin Buu story arcs, Popo came up with the idea of having Goten and Trunks do the Fusion Dance after everyone else had run out of other ideas. The family and friends of the Z Warriors took refuge from Majin Boo on the Heavenly Realm. Popo also observed the Fusion of Trunks and Goten. A day later, Super Boo found the Heavenly Realm and allowed them to live for a short time. While there, Super Boo used his Human Extinction Attack to kill all of the people of Planet Earth except for Mister Satan, his dog Bee, and the family and friends on the Heavenly Realm. When Super Boo escaped from the Hyperbolic Time Chamber, Popo and the rest were turned into chocolate and eaten. Popo was later revived and gave his energy to help Goku make the Genki Dama to destroy Kid Boo.
When Goku first reached Kami's Lookout in the anime filler, he encountered Popo seated on a Persian rug (likely the same one he used to fly with in Dragon Ball Z) and with what appeared to be a light fog covering him and birds on his shoulders. After they greeted each other and battled, Goku put up a good fight against the Genie and attempted a Kamehameha at him, only to have it literally swallowed by Popo in return. Goku then tried to defeat Popo by using the "punch that beat King Piccolo" only to have him evade it with no difficulty.
During the Majin Buu Saga, he had a brief match with Goten and Trunks in Super Saiyan form, respectively. During the fight, he blocked several hits and even dodged a kick. After Trunks managed to kick him once, he appeared uninjured, thus proving him a far stronger character than others assumed he was. Popo himself stated that Kami was on a different plane of power than his own, however, and Goku, after the three years spent training with Popo, was stated and shown to far surpassed Kami's own skills and strength. Five years later, however, he was practically helpless in a fight against Raditz, even with Piccolo's aid, and had to sacrifice himself just to beat the 1,200 battle power soldier who the later villains, Vegeta and Nappa, would consider to be "that weakling". Given these statements from the manga, Popo standing his ground against them in their Super Saiyan forms was undoubtedly one of the inconsistencies regarding power and plots.
Dragon Ball GT
Popo had a very small role in Dragon Ball GT. In the first episode, he prepared to restore the Heavenly Realm after Goku and Oob had finished their intense training and damaged the place almost entirely. He remained as a background character for most of the series. He was last seen during the flashback montage sequence in the final episode.
Popo appeared in Dragon Ball Z: The Return of Cooler, Dragon Ball Z Gaiden: Saiya-jin Zetsumetsu Keikaku, and Dragon Ball Z: Bardock: The Father of Goku (seen in one of Bardock's visions)
Popo appeared in Dragon Ball Z: Kyōshū! Saiya-jin.
- Instantaneous Movement – Unlike Instant Transmission, he can transport instantly to a desired location on Earth without requiring the use of an energy signature to home in on. He is first seen using this technique when he transported with Bulma on his flying carpet to Yunzabit Heights, which was the region where Kami's old spaceship crash-landed and needed to be restored.
- Magic Materialism – A magical ability used to create objects from seemingly thin air. Mr. Popo can bring out a rolled-up ball of carpet from nowhere and throw it upon the ground which, instead of actually touching the floor, opens up in mid-air and becomes his magical flying carpet.
- Japanese dub: Toku Nishio (DB, DBZ, DBGT, DBZ Movie 6); Kawazu Yasuhiko (Dragon Ball Kai)
- Ocean Group dub: Alvin Sanders (Saiyan Saga and Namek Saga), French Tickner (Android Sagas onwards)
- FUNimation dub: Chris Cason (DBZ Season 3 originally, Dragon Ball Z Kai); Christopher Sabat (Everything else)
- Brazilian dub: Cesar Marchetti
- The Dragon Ball Collectible Card Game lists Popo as being of the Human race.
- One of Popo's possible character designs is a Dinosaur-like creature who resembled a Chicken hatchling. The other looks like Kami with a mustache.
- In the event that a Kami dies before finding a successor, Popo (who is immortal) is responsible for finding one.
- To some, Popo is claimed to be a variant of darky iconography, a "racist" style of caricature. On May 4, 2000, an article written by children's book author Carole Boston Weatherford claims that Mr. Popo, along with pokémon #124, Jynx, are derogatory stereotypes because of the black skin, big lips, and, for Popo, lack of teeth. In 2004, Viz began to downsize Mr. Popo's large lips digitally in the American release of the manga. Pokémon had changed Jynx's face and hands to purple.
- Popo seems to be able to speak the Namekian language taught to him by Kami (even though Kami found out he was from Planet Namek only a short while before his death).
- In the 4Kids version of Dragon Ball Z Kai, Popo is recolored royal blue. This is similar to what happened to Oil Man of Mega Man: Powered Up when he was released overseas due to being considered "racially incorrect".