Goku is the main character of Dragonball Z. He is a Saiyan who was originally sent to Earth when he was an infant to kill everybody. However, he fell down a cliff and hit his head and didn't remember anything, and was taken in by a human named Gohan. Now he defends Earth. He married Chichi and had two sons, Gohan and Goten. He didn't know he was a Saiyan until he was told by Radditz in the beginning of Dragon Ball Z, and that his real name is Kakarot. Even though he is a 3rd class Saiyan he is usually the strongest character for most of Dragon Ball Z, even more powerful than Vegeta who is the prince of the Saiyans. Goku got his tail surgically removed when he was a baby so the light of a full moon no longer turns him into an Oozaru.