Mr. Popo is one of the longest-tenured characters in Dragon Ball, yet it's been quite some time since this mysterious being received any of the series' attention. It's been so long since Mr. Popo got some time to shine, that newer fans might be more familiar with the character's hilarious re-imagining in the popular YouTube series, Dragon Ball Z Abridged. Let's look back at what we know about Mr. Popo's history, and ponder the age-old question, "what is he?"
Mr. Popo first appeared in Dragon Ball after Goku climbs onto the Lookout in search of a way to revitalize the Dragon Balls in the wake of King Piccolo's death. Mr. Popo decides to test Goku with a fight and proves himself to be worlds above the cocky child as a martial artist, adding insult to injury by literally eating Goku's Kamehameha Wave. Mr. Popo even effortlessly avoids Goku's devastating punch that had defeated King Piccolo. Goku would spend the next three years training on the Lookout under Mr. Popo, learning to sense Ki and developing the Super Kamehameha.
Mr. Popo would prove himself an effective teacher, capable fighter and quick thinker throughout his time in Dragon Ball Z. He trained Krillin, Tien Shinhan, Yamcha, Chiaotzu and Yajirobe in preparation for the Saiyans, fended off Goten and Trunks as Super Saiyans without a scratch and saved Dende from Majin Buu's rampage by throwing him over the side of the Lookout. It was even Mr. Popo's idea to have Goku teach the Fusion Dance to Goten and Trunks upon hearing Goku lament that he would be unable to do so with Gohan or Vegeta after their respective defeats at the hands of Buu.
Like many other characters, Mr. Popo has come down with a serious case of Not-Goku Syndrome in Dragon Ball Super. Though he still resides on the Lookout with Dende, Mr. Popo has been entirely uninvolved with the recent conflicts, despite serving as something of a mentor and voice of reason in Dragon Ball and DBZ. Mr. Popo did briefly remind everyone that he is a capable fighter when he fearlessly warned Vegeta in Super that he would ban the Saiyan Prince from using the Hyperbolic Time Chamber if he kept destroying it.
So, who, or what is Mr. Popo, exactly? He was born in the Other World and was already at least 1,000 years old when he was first introduced in Dragon Ball. He served Kami for centuries and served Kami's predecessors for an unknown length of time, so 1,000 years is likely a low estimate of his true age. Given his birthplace and his immense lifespan, it seems safe to say that Mr. Popo is a deity of some kind. Tasked with the role of assistant to Earth's Guardian and caretaker of the Lookout, he is generally bound to the Lookout but has been shown to leave it on extremely rare occasions.
When the Guardian is away (or dead), Mr. Popo assumes command of the Lookout, but it's unclear how much, if any, Guardian-like duties he takes on during such a time. He does act as a mentor to Dende when the young Namekian first becomes Guardian, so Mr. Popo has certainly learned a thing or two during his eons of service. He forms deep emotional bonds with the Guardians that he serves, displaying extreme distress whenever a Guardian is in peril. Mr. Popo is a calm, patient man, which is certainly beneficial when forced to endure the constant chaos that has plagued the Lookout ever since Goku first climbed up as a child.
Mr. Popo gives off Angel vibes with his "I could if I felt like it" energy, so there may yet be more to learn about this mysterious deity who literally eats energy blasts for breakfast. Even though it seems possible that we've learned all we're ever going to know about Mr. Popo, Dragon Ball Super's manga continues to surprise its readers with each new chapter. A faithful servant, and a surprisingly skilled tennis player despite being older than sports, Mr. Popo plays his role in Dragon Ball to perfection and will hopefully play an important role again someday.