Dragon Ball Z: Fusion Reborn

The two gunmen proceed to shoot rockets at Buu's house. Hercule runs up to the hill they're on and pounds each of them. Buu is able to heal the dog, and the three friends continue having fun. Buu rebuilds his house to look like the dog. While Hercule is cooking a meal for Buu, one of the gunmen sneaks into Buu's house and shoots the World Champ. Buu starts to lose control of himself. After he heals Hercule, he instructs him to get away. Buu begins giving off more steam than ever, and the steam is congealing in the sky. It forms the evil side of Buu, a tall, thin, gray version of Majin Buu. Evil Buu flies over to the gunman and blasts him into nothing.