Piccolo

The son of King Piccolo, Piccolo followed his father's plans, until the beginning of DBZ. During the Saiyan Saga, he means only to join the side of good, for the time being, but ends up on their side for good. Gohan helped him to become the Piccolo we now see. Even Goku helped. He later fuses with Nail and Kami, which makes him the strongest fighter on Earth. (For the time being.) Though he is a strong fighter and helps out in every series a lot, he can not match a Super Saiyan's powers.