Vegeta

This is one of the main characters in DBZ. He turns out to be one of Earths greatest challenges until Goku gets there and fights his hardest and is the victor. As current events cause Goku and Vegeta to meet again on the Namek/Freiza saga, they team up and destroy Freiza and become partners. Soon, they learn how to fuse to become Vegetto and Gogeta. But Vegeta will only fuse with Goku when he is near death, because he cant stand the thought of being a part of Goku's body.