TV-Series
Description
Mr. Boo is the kindhearted remnant of the original Majin Buu, having been separated from his evil half after the events of Dragon Ball Z. He is the rotund, pink-skinned being who chose to live peacefully on Earth following the defeat of Kid Buu. His background is rooted in his origins as a primordial magical entity created by the witch Marba, but after absorbing a gentle Kaioshin, his nature became permanently tempered with innocence and good will. By the time of Dragon Ball GT, Mr. Boo has fully settled into a quiet life in the care of Mr. Satan, having left his destructive past behind.

In terms of personality, Mr. Boo is childlike, naive, and highly affectionate. He displays a simple, playful demeanor and a strong attachment to his friends, particularly Mr. Satan. He is easily amused, enjoys eating, and often acts on impulse, but this innocence is paired with a genuine sense of loyalty and protectiveness toward those he cares about. Unlike his former self, he no longer possesses a cruel or violent streak; instead, he is gentle and helpful, though he can still access his immense power when the situation demands it. His motivations are straightforward: he seeks companionship, comfort, and a peaceful existence, and he acts to defend his loved ones when they are threatened.

Mr. Boo's role in Dragon Ball GT is that of a supportive ally rather than a primary combatant. He remains on Earth while Goku and the others travel into space, but he becomes directly involved during the Baby saga. When Baby possesses many of Earth's inhabitants and threatens Uub, Mr. Boo steps in to protect the young boy. He intervenes by intercepting Baby's Revenge Death Ball and redirecting it safely, saving Uub from certain death. He also reveals the deep connection between himself and Uub, explaining that they were once one being a long time ago. He proposes that they fuse together once more to combine their power and defeat Baby, showcasing his willingness to sacrifice his individual form for the greater good. This moment is one of his most significant contributions in the series, as it directly impacts the fight against the main antagonist of that arc.

Key relationships define much of Mr. Boo's existence. His bond with Mr. Satan is the most important; Mr. Satan served as his caretaker and friend following the Buu saga, and the two live together in a comfortable, humorous household. Mr. Boo's relationship with Uub is particularly unique, as Uub is the reincarnation of Kid Buu, making them two halves of the same original being. Mr. Boo acknowledges this connection and views Uub as someone he can unite with to achieve greater strength. He also maintains a friendly relationship with the other Z-Fighters, though he is less directly involved in their battles than he was in Dragon Ball Z.

Throughout Dragon Ball GT, Mr. Boo does not undergo any major personal transformation or growth; his character remains consistent as a gentle, loyal companion. However, his willingness to merge with Uub represents a mature acceptance of his past and a selfless desire to help his friends, showing that he has fully embraced his role as a force for good.

Mr. Boo retains most of the extraordinary abilities he possessed in his previous form, though he uses them much less aggressively. He has incredible regenerative capabilities, allowing him to recover from almost any injury almost instantly. He can stretch and morph his body in various ways, manipulate his own mass, and heal other living beings. He retains the ability to transmute matter, though he does not use it offensively in GT. He also possesses immense physical strength and durability, as well as the capacity to absorb attacks and energy. His power level, while still formidable, is presented as being on par with or slightly less than his prime, but he remains one of the most powerful beings on Earth. His most notable demonstration of ability in GT is his defensive interception of Baby's attack, which highlights his continued relevance as a protector despite his peaceful lifestyle.