Attendants are beings who serve various deities. They have a variety of duties ranging from assisting their deity, teaching them, or keeping them in check.
List of Attendants
Mr. Popo is an attendant who serves the long lines of Guardians of Earth at The Lookout. He works as a groundskeeper and as a body guard to test in physical ability if anyone is worthy of seeking an audience with the guardian of Earth.
During the Majin Buu conflict, Mr. Popo saves the current Guardian Dende from the rampaging Super Buu by seizing Dende and hurling him off of the lookout bravely sacrificing himself to save Dende's life.
God of Destruction attendants
All of the Gods of Destruction are shown with an attendant following them. Whis is the attendant to Beerus, the God of Destruction for Universe 7, while Vados is the attendant for Champa the God of Destruction for Universe 6.
These attendants serve as martial art teachers to their Gods of Destruction, and are physically stronger than the Gods. They are tasked with keeping the Gods of Destruction in check, and will intervene when the God goes too far. They also perform trivial duties for the Gods of Destruction such as preparing meals for them.
All of the attendants seen are Angels, watching over their respective God of Destruction, if the God of Destruction were to die they will cease to function until the next God appears, they also at times watch over the Supreme Kais since their lives are linked to their respective God of Destruction.
Supreme Kai attendants
Supreme Kais are shown to have attendants. The attendant for the Shin is Kibito, while an unnamed attendant serves Fuwa. These attendants mainly serve as assistants to their superiors, and unlike the God of Destruction attendants they are weaker than their bosses.
In Xenoverse and Xenoverse 2, it is revealed that Xeno Trunks was forced to serve as Supreme Kai of Time Chronoa's attendant as punishment for his sin of using the Time Machine and altering history, though it is revealed that in reality Xeno Trunks had committed no crime when he originally used the Time Machine as Chronoa only made it a crime against the natural laws of Universe 7 after Trunks' use of the Time Machine, which resulted in the first time distortion in history of Universe 7. Instead Chronoa lied to Xeno Trunks about it being a sin as she was in need of an attendant/assistant, though she was surprised that Xeno Trunks would take her words to heart and dedicated himself to working for her to make up for his sin. This shows that even mortals like Xeno Trunks can serve as Attendants to a Supreme Kai.
In the Dragon Ball Super manga, it is revealed that Supreme Kai attendants possesses Healing powers, though Shin reveals these powers are lost if an attendant is promoted to the position of a Supreme Kai, as Shin laments the fact that he would still possess his healing powers if he was still an attendant, during the battle with Goku Black and Future Zamasu. It is also revealed that Future Zamasu retains his healing powers cause he never became a proper Supreme Kai and was technically still an attendant. The manga further confirms that mortals becoming attendants is canon (at least in the manga), as Future Trunks is revealed to have become an attendant to Future Shin and thus possesses healing powers as a result. It is also shown that even if the Supreme Kai they served has died (as in the case of Future Trunks and Future Zamasu) the attendant retains their healing powers. It should be noted that an attendant may not even be aware of these powers as Future Trunks was unaware of it until he revealed his status as an attendant to the late Future Shin, to Future Shin's main timeline counterpart and Gowasu. Also due to his lack of knowledge and unfamiliarity with those powers, Future Trunks healing abilities were limited unlike Future Zamasu who could heal Goku Black repeatedly without trouble.
However attendants possessing healing powers as a result of their position only occurs in the manga as both attendants and Supreme Kais possess healing abilities in the anime and Future Trunks only receives instructions from Shin.
Zen-Oh possesses his own attendants that escort him to his desired location and act as his bodyguards, preventing anyone from getting to close to their master.
Main article: Zuno's attendants
Zuno has own attendants that keep uninvited guests or the one's who don't have an appointment away from Zuno.