Raditz

"You were born on the Planet Vegeta. You are a space fighter, a Saiyan Warrior. Just like me.  Allow me to introduce myself, I'm Raditz.  Your big brother."

"I see the fire in your eyes, brother; you should come with us. It's in your blood, you love to fight."

- Raditz to Goku.

"You are a disgrace to all Saiyans! Now, prepare to die!"

- Raditz to Goku.

"After all, he's my nephew. It would be a shame if I had to hurt him."

- Raditz threatening to kill Gohan.

Raditz is the older brother of Son Goku and the first villain in the series Dragon Ball Z and in the Dragon Ball Z Kai series. He is also the tertiary antagonist of the Saiyan Saga.

He is one of the last surviving members of a race known as the Saiyans, and comes to Earth in search of his brother, to see if he had taken over Earth, as he was supposed to. However, Goku hit his head as a child, and lost all memory of his mission and who he was. Raditz is also the first Saiyan to come to Earth, and at that point he was much stronger than Goku, and Piccolo, who had teamed up to fight him.

Past
Raditz, along with Nappa and Vegeta returned from their conquest on the Planet Shikk. However, when they returned, they were met with insult rather than congratulations by Dodoria, Zarbon, and Freeza. While Raditz was visibly hurt and angered by this, Nappa loses control and attempted to attack all three. But Vegeta orders his comrade to stand down, knowing that he would not stand a chance against them.

Arrival on Earth
Upon arriving on Earth, Raditz encountered a farmer, who tried to shoot him, but Raditz caught the bullet and sent it back at him, killing him. During his search for Kakarot (Goku), Raditz encountered Piccolo, Goku's old enemy from the Tenkaichi Budokai five years ago, whose attack had no effect on him. Raditz was about to attack when his scouter picked up Goku's power level, and he headed off to find him.

Raditz and Goku
When Raditz finally found Goku, he was shocked to see that his brother has changed and also discovers that he failed to complete the mission that he was supposed to, due to having his Saiyan characteristics permanently gone after having a nasty bump on the head. He told Goku, and his friends that he is from another planet and that he is an alien called a Saiyan. He also told them that he, Goku and two others were the only members of the Saiyans and tells Goku that he is not from Earth, but that he is a Saiyan and is part of the Saiyan race. Raditz then reveals to Goku and his friends that he is Goku's brother.

Confrontation
Raditz kidnapped Goku's son Gohan to make him rejoin the Saiyans and locked him in his space pod. Goku and Piccolo teamed up to fight him, but Raditz was still stronger, managing to destroying one of Piccolo's arms. Piccolo was left with no choice but to use his Makankosappo, but Raditz dodged it. He then attempted to attack, but at that moment, Goku snuck behind him and grabbed his tail, causing him agonizing pain. However, he tricked Goku into letting him go, then stomped on him.

Raditz's Defeat
Gohan unleashed his hidden power and broke free of Raditz's space pod. He then flew and hit his uncle with his head, damaging him. As Raditz was about to kill Gohan, Goku gets him into a full nelson, sacrificing himself to defeat his brother, as Piccolo used the Makankosappo on them, mortally wounding them both. However, Raditz did not immediately die from this attack; after his scouter transmitted what Piccolo said about the Dragon Balls to Nappa and Vegeta (and Freeza), he was laughing at Piccolo, who then finished him off.

This was also the beginning of the Z Warriors vs. the Planet trade organization.

Powers and Abilities
Like nearly every villains in the Dragon Ball series, Raditz can fly, generate multiple ki Blasts, and possesses superhuman abilities. He, like every other Saiyan, can only turn into an Oozaru ape during a full moon.

Oozaru
Raditz can transform into an Oozaru ape when he looks at the moon, absorbing Blutz Waves. This form multiplies his power by ten.

Soul
Spirit Raditz is a form of Raditz which appears in Attack of the Saiyans, it is the form Raditz takes in Otherworld, and in this form, Raditz is strong enough to take on Goku (who had finished training with Kaio), Gregory, and Bubbles.

Personality
Like all Saiyans, Raditz is brutal, mean, intolerant, prideful and sadistic. He loves to fight and he will gladly kill any member of his family if it means coming out on top. Despite being a heartless brute, Raditz is a coward in the face of death. To prevent being killed by Piccolo's Makankosappo, while Goku twists his tail in order to subdue him, Raditz "promises" to leave Earth and never come back. Because of his naivete, Goku releases him and he fights back.

Trivia

 * Piccolo_kills_Raditz.jpgz's actual death was never shown onscreen (as the last we see of him, Piccolo is raising his fist above him to deliver the deathblow), and his corpse remains offscreen when Bulma and Kuririn take his scouter, suggesting that it was not a pretty sight what Piccolo did to him. His body is, however, seen from a distance at times (particularly the title screen of the episode), and clearly seen in the redub, and the ground around him appears cracked and damaged, though there are no visible markings on it as to how or where the deathblow was struck. Dragon Ball Z Budokai Tenkaichi suggests that Piccolo smashed him with his fist to kill him. It is in fact possible, though unlikely, that Raditz survived.