Radditz:

Radditz is Son Gokou's older brother, also a weak Saiyajin at birth but still stronger than Gokou when they first meet. He arrives on Earth in the beginning of the Dragon Ball Z series to see if his younger brother was able to conquer it. When he discovers his brother has turned to the side of good, he kidnaps Gokou's son, Gohan. With the help of Piccolo, Gokou's former rival, they defeat and kill Radditz. However, Gokou is killed as a sacrifice in this battle when Piccolo shoots his Makankosappo.