Piccolo

 Goku's one time archenemy, Piccolo is the second strongest being on the Earth. He has powerful energy blasts, can split into two or four separate entities, and has the ability to regenerate limbs. Originally from the far away planet Namek, Piccolo starts off fighting Goku to rule the world. When the Saiyans arrive he joins forces with Goku. At first it is an uneasy alliance, soon enough their bond becomes stronger. While training Gohan, Piccolo develops a special bond with the little boy. Through Gohan, the only person who has ever been a friend to him, Piccolo starts changing for the better.