Kid Buu was created by Babadi and destroying planets by his own amusement millions of years ago. Now he came back from the events of Super Buu and Majin Buu. Kid Buu destroyed Earth with his planet burst. Now the final battle with Goku and Vegeta. Now, he is destroyed by Goku's Super Spirit Bomb and was reincarnated by the name Uub. Kid Buu is the one that killed all the supreme kai's except Eastern Supreme Kai. After absorbing Southern Supreme Kai, Kid Buu transformed into fat Majin Buu, which greatly reduced his power.