Gogeta

One of the most powerful characters in all of Dragonball/Z/GT, Gogeta is the result of the fusion between Goku and Vegeta. Gogeta appears only in DBZ Movie 12, and in GT. Done by the fusion dance Gogeta is many times more powerful than either Goku or Vegeta alone. Gogeta is a totally different person, and so his personality is completely different than either of the two Saiyan's that fused to become him. Gogeta's power is simply enormous as he takes out Janemba effortlessly in DBZ Movie 12 after reaching Super Saiyan 2. By GT, his power is almost beyond comprehension as Super Saiyan 4 Goku and Vegeta fuse to create Super Saiyan 4 Gogeta, probably the most powerful character in the entire history of the series. His special attack is Big Bang Kamehameha. The only reason that Gogeta does not completely obliterate Omega Shenron is because of his own cockiness. Gogeta toys with the Dragon but happens to defuse early because of his enormous power.