Bull Borgnine isn't your average 12-year-old. There are three versions of him because he has not one, but two alter egos! While in his first state, he has dot eyes and is normally quiet. He also laughs a lot in the middle of any situation. But when he gets excited or most times while handling his B-Daman, Helio Breaker, he can transform into another version of him who is a much more handsome guy. His hair grows a bit longer and covers his left eye and his eyes get more bigger. While the other alter ego has spiky, red hair.
At first, Bull stole other people's B-Daman but after meeting and befriending Yamato Delgado, he changed ways and B-DaBattled fairly. Bull, at first, had no real position in the group of him and his friends, but later on found his true spot as being the B-Daman mechanic in the group. He now repairs his friend's B-Daman when they need tuning up or any repairs on damages.
(Source: Absolute Anime)