Raditz's History
Background
Raditz was born to Bardock and Gine sometime before Age 736. Raditz was born with a power level high enough to become an upper-level warrior and was assigned to the same group as Nappa. Later, Vegeta was added to the group too.
Jaco the Galactic Patrolman
Raditz is on an extraterrestrial planet with Prince Vegeta, Nappa, and two other unknown Saiyans as part of an invasion force. Raditz and Vegeta hear the message from Frieza through their scouters that he needs the Saiyans to return to Planet Vegeta. Raditz questions if they're returning to the planet but Vegeta wants them to pretend as if though they didn't hear it. A month later, Frieza destroys Planet Vegeta, killing most of the Saiyans while Vegeta's platoon (including Raditz) is still away.
Before his parents died in the destruction of Planet Vegeta, Raditz is told by them about what had happened to his brother, Kakarot. However, Raditz was under the impression that Kakarot was officially sent off to Earth to conquer it when, in reality, his parents had stolen a space pod and sent Kakarot there unauthorized to save him due to Bardock's premonition and fears that Frieza was planning to destroy the Saiyans because of his fear of the Super Saiyan legend, as evident by the Frieza Force's inquiries into the legend and Frieza's orders for the Saiyans to return to Planet Vegeta.
Because Prince Vegeta chose to ignore this order, this saved himself, Raditz, Nappa, and the two other Saiyans from being among the Saiyans killed in Planet Vegeta's destruction.
Between Jaco and Dragon Ball Z
In an anime-only flashback in the Frieza Saga, sometime after the genocide of the Saiyans, Raditz, along with Nappa and Vegeta, return from their conquest on Planet Shikk. However, they are met with insult rather than congratulations by Dodoria, Zarbon, and Frieza. While Raditz is visibly hurt and angered at this, Nappa loses control and tries to attack Frieza, Zarbon, and Dodoria, but Vegeta orders his comrade to stand down, knowing that he would not stand a chance against them.
Dragon Ball Z
Saiyan Saga
At the start of Dragon Ball Z, Raditz arrives on Earth in a space pod, in search of a man named "Kakarot," later revealed to be Goku. After he incapacitates a farmer who found his space pod, Raditz detects a power reading on his scouter and assumes it is Goku. He tracks down the source of the energy and comes face to face with Piccolo, Goku's mortal enemy at the time. Raditz asks Piccolo where he can find "Kakarot", but Piccolo refuses to tell him, warning him to leave Earth at once. Raditz laughs at Piccolo, who fires a powerful attack at Raditz, leaving him unscathed, which shocks Piccolo. Just as Raditz prepares to destroy Piccolo, he detects another power level, and this time he knows that it is Kakarot, the one he is looking for.
Raditz tracks the power level down to the Kame House, where Goku was introducing his son Gohan to Bulma, Krillin, Master Roshi, and Turtle, while also enjoying a reunion. Raditz identifies Goku as Kakarot, and informs Goku that he is his big brother, who arrived on Earth to find him. When Goku asks where Raditz came from, Raditz tells Goku that they are both Saiyan warriors, and tells him the history of the Saiyan race and their entrepreneurial ways of conquering planets and selling them for profit. Goku and Krillin express their disgust at Raditz and tell him to leave.
Krillin proposes to escort him off the island, which results in him being smacked in the face by Raditz's tail, thus revealing his tail, one just like Goku used to have and which Gohan has. When it becomes clear to Raditz that Goku is not coming with him, Raditz sends Goku plummeting to the ground with a powerful knee strike to the stomach and kidnaps Gohan (who still has a Saiyan tail), holding him for ransom. He informs Goku that if he ever wants to see Gohan again, he should eliminate one hundred people from Earth and bring them all to him by the next day. Laughing, Raditz flies off with Gohan in his hands.
Later, he shuts the crying Gohan in his space pod, unable to stand his crying. Raditz is surprised to find that his scouter reported a power level of 710 for Gohan, which Raditz dismissed as a malfunction because it would mean that the child was even stronger than his father. Shortly afterwards, Raditz sees Goku and Piccolo who have joined forces to beat him, and since his scouter accurately warned him of their approach, he came to the realization that Gohan may actually be as strong as his reading said.
Seeing that Goku has not only refused to join him, but also brought Piccolo as a reinforcement, Raditz declares his younger brother a shame to their race and sentences him to death. A battle commences, and Raditz soon proves he is far stronger than both Goku and Piccolo combined and easily overwhelms them. Raditz even manages to blast off Piccolo's left arm. The tables turn when Piccolo reveals he created a special attack that may be able to kill Raditz, the Special Beam Cannon. However, the attack needs several minutes to charge up, meaning Goku has to fight Raditz alone for five minutes. As Piccolo prepares the attack, Goku and Raditz battle it out, yet Raditz easily takes the lead. Goku, however, leaps into the air and launches a Kamehameha.
Raditz is startled that he is able to increase his power into one spot, and is even more shocked to find Piccolo's rising as well. Before he can think, Goku launches his attack. Raditz tries to run from it, but cannot. He is, however, able to nullify it with his hands. Raditz then launches a more powerful attack back at Goku, badly wounding him and knocking him out of the sky. He tries to make the kill, but soon sees Piccolo's attack ready. To his dismay, the attack is too powerful for him to block, and he is shocked that Piccolo could summon that much power. Piccolo launches the attack, but Raditz is fast enough to dodge it, yet it does pierce through one of his shoulder pads, also injuring his shoulder. He almost kills Piccolo, but is stopped by Goku, who grabs Raditz's tail, causing immense pain. As Piccolo prepares the attack, Raditz begs for mercy from Goku with brotherly words ("I would never harm my own flesh and blood!"). Piccolo tries to warn Goku it is a trick, but the Saiyan's mercy gets the better of him. Goku lets go of Raditz's tail, and Raditz takes advantage by throwing his brother to the ground, stomping on his chest multiple times, crushing his ribs. Goku calls the trick dirty and Raditz in turn says that he is a first-class warrior, and never hesitates to kill anyone, even his own brother. He also edges Piccolo for his attack, but Piccolo says it is useless.
While Goku cries out in pain with Piccolo helplessly watching, a power suddenly erupts and Raditz's spacepod explodes. Just as Raditz prepares to kill Goku, an enraged Gohan emerges and flies straight into Raditz's chest, seriously injuring him. Incensed and in awe of the small child, Raditz whacks Gohan across the field and limps over to him, preparing to kill him in fear of his power, which he complimented as he approaches. Before this can happen, however, Goku grabs Raditz from behind in a Full-Nelson, giving Piccolo enough time to power up another Special Beam Cannon. Raditz, fully aware that the beam will be enough to finish the both of them, implores Goku not to sacrifice himself for "these Earth dogs" and let him go, but Goku refuses. Piccolo fires the Special Beam Cannon and hits both Raditz and Goku square in the chest, mortally wounding them both.
As he lays dying, spitting blood and suffering on the ground, Raditz genuinely acknowledges Goku's death (as well as his own), but Piccolo tells him about the Dragon Balls, that will revive Goku shortly after the wish is made. Raditz, however, retorts that his scouter is also a transmitter, and his two Saiyan comrades have heard everything and will come for the Dragon Balls to wish him back. Laughing his head off, Raditz is finished off by Piccolo, and dies shortly before Goku does so. Using his scouter to transmit Piccolo's message, Raditz calls for help from his two fellow Saiyans, Nappa and Vegeta, who eventually journey to Earth to gather the Dragon Balls, not to revive Raditz (as Raditz believed), but for immortality. In the Other World, Raditz attempts to fight King Yemma, who overpowers him and sends Raditz to Hell.
After Goku dies, Bulma and Krillin remove Raditz's scouter from his corpse. Bulma modifies the scouter so it can display numbers rather than the alien symbols that are used by Frieza's forces. The scouter later explodes when the revived Goku powers up during his fight with Vegeta.
Dragon Ball Super
When Goku and Krillin were sent into a forest to retrieve a special herb for Master Roshi, an illusion of Raditz and many other villains from the Z-Fighters' past show up to challenge the duo.
