Mister Buu

Mr. Buu (May 8, 774 - 790) was the good half of Majin Buu, identical to Buu's "fat" incarnation. He split from the original after a moral conflict between Buu's newfound goodness and his desire for revenge on the gunman (Van Zandt) who shot his puppy, Bee. Mr. Buu battled his evil half (Evil Buu), only to be eaten by him, creating Super Buu. Mr. Buu remained dormant inside Super Buu, only able to prevent him from killing his friends Hercule and Bee, until he was torn free by Vegeta- reverting Super Buu to Kid Buu. Unassimilated but still trapped inside Kid Buu, Mr. Buu was only freed when he internally tried to stop Kid Buu from killing Hercule on the Supreme Kais' planet. Spit out by Kid Buu, Mr. Buu engaged him in battle, helping delay him long enough for Goku to gather the energy for the Spirit Bomb that destroyed Kid Buu.

Returning to Earth with Hercule, Mr. Buu continued to hang out with his friends. Despite the fearsome reputation he'd built up as Majin Buu, Mr. Buu was able to live normally after the Dragon Balls wiped away the people of Earth's memories of him.

Dragon Ball GT

Mr. Buu eventually took on Baby after he possessed the populace of Earth, only to be exploded- he then chose to merge with Uub, the good reincarnation of Majin Buu, creating "Majuub." Mr. Buu's spirit remained, however, preventing Uub from defeating Hercule at the World Martial Arts Tournament and thus discrediting the Earth's hero.