Bibidi was an evil alien wizard responsible for awakening the demon Majin Buu millions of years prior to Dragon Ball Z. Due to his actions and role, he is the posthumous overarching antagonist of the Majin Buu Saga.
He was voiced by Duncan Brannan.
Though he only appears briefly, Bibidi is the one who created Babidi and awakened Majin Buu, and is thus responsible for the entire Buu story arc. He is also the oldest and earliest villain in the series, for the events that he was involved in predate the rest of the story by millions of years.
After Bibidi awakened Kid Buu from his slumber, he then started taking him from planet to planet to destroy them all in his quest to dominate the universe. Early on, Buu almost recklessly killed Bibidi, who then told the monster that he was his "dad" in an attempt to control him. Later, he took Buu to the world of the Kais, where the monster killed the Western and Northern Supreme Kais, and absorbed the Southern Supreme Kai, becoming Super Buu in the process. He then tried to kill Eastern Supreme Kai, but the Grand Supreme Kai protected him, and when Buu absorbed him, he became the much weaker and less evil Fat Buu due to the goodness of Grand Supreme Kai's soul.
Later, Bibidi created a magical ball to seal Buu inside of between conquests, and eventually brought the ball to Earth. However, before the wizard could release Buu again, Supreme Kai killed him, and the ball of Buu was left dormant for millions of years until his doppelganger Babidi picked up where his "father" left off.