In Between Majin Vegeta and Majin Buu Sagas
Gokou and Majin Vegeta's fighting raised enough energy for Buu to be revived. The ball that Buu is restrained in breaks apart after Gohan unleashes a massive assault on it. The ball opens up and nothing appears... at first. Then Gohan notices a cloud of pink smoke overhead and the smoke slowly forms in to Buu.