Son Goku
Son Goku is the primary hero of the Dragon Ball series. The series started out with Goku as a child of age 12. Once he grew up and his son was born, the TV series' name changed from Dragonball to Dragonball Z. At the end of the series, Goku was roughly 45 years old. Goku is a Saiyajin whose native world is the planet Vegita. He was sent to Earth in a space capsule right after he was born so he could conquer the planet. However, he hit his head and lost his "programming," thus becoming the kinder, gentler Goku we see in the series. Goku was raised as a human on Earth, and did not learn of his true nature until his brother Radits came to Earth...
Later, when Goku's rage was awakened by witnessing the death of his friend Kulilin, his Super Saiyajin power was awakened. When he goes Super-Saiyajin his eyes turn green and his hair gold. Currently, Goku can go to the 3rd stage of Super-Saiyajin power.