Species: Alien Monkey
First Appearance: Dragon Ball Z manga, "Deeds Done by the Full Moon," anime episode "The End of Snake Way"
Other Appearances: Bubbles also appeared in the spin-off anime Dragon Ball Super and Dragon Ball GT, as well as the films Dragon Ball Z Gaiden: Plan to Eradicate the Saiyans, Dragon Ball Z: Boak Unbound, Dragon Ball Z: Broly - The Legendary Super Saiyan, Dragon Ball: Heya! Son Goku and Friends Return!!, and Dragon Ball Z: Battle of Gods.
Merchandising: Bubbles has likely been immortalized in toy form in Japan, but I don't know if he was part of any US toy line. He is featured in the app Dragonball Z: Dokkan Battle, primarily as one of the Awakening Medals required to advance characters beyond a certain level.
Biography: Bubbles is the pet monkey of the North Kai, aka "King Kai," and lived with him on King Kai's planet. Since that planet's gravity is ten times that of Earth, you can imagine how strong Bubbles is as a result. When King Kai is training warriors (most particularly Goku, the lead character in Dragonball Z, as well as Piccolo, an alien Namek who is at times Goku's friend and ally, and other times his foe and rival). When Goku arrived on King Kai's planet, he first mistook Bubbles for King Kai, and thought he would have to act like a monkey to begin training. When the real King Kai showed up, Goku learned his first training was to catch Bubbles, something which took him 40 days to accomplish (when Piccolo showed up, he did it almost effortlessly). Later in the saga, when Cell self-destructed on King Kai's planet, Bubbles was killed.
Powers: Bubbles has strength approximately 10 times that of an Earth monkey, due to being accustomed to ten times greater gravity than Earth's. His dexterity is also enhanced by this exposure. Bubbles is also very intelligent, enough so that when Goku has been injured, Bubbles knows enough to feed him a Senzu Bean to revive him.
Miscellaneous: Bubbles' name may have been a reference to Michael Jackson's pet chimp. He resembles the Saiyan Great Ape form in many ways, although with his pointed ears, I thought his appearance owed a lot to the Robinsons' pet space chimp, Debbie.
Dragon Ball Z is one of the longest-running manga and anime in Japan, and has a large US fandom as well, probably helped most when Cartoon Network started running episodes daily. The lead character, Goku, is a member of the Saiyan race, and one of the last surviving members of that race. He was brought to Earth, where he began having adventures even as a child (in Dragon Ball), later marrying an Earth woman and having two children, both boys. He was originally trained by Master Roshi, and is known for his special attack power "Kamehameha," although he also has super strength, flight, and teleportation powers. The series is known for its epic battles, often lasting over a dozen episodes or more, with a huge cast of characters. The name of the manga and anime is a reference to the legendary Dragonballs, which can be gathered together and used to make a wish from the dragon Shenron, which seems to be most often used to wish back to life people who've been killed by the current main villain, once that villain has been defeated.