A member of the Red Fury Brotherhood, Reddjak also served as the captain of the Blood Brother. This near-Human pirate initially served the Galactic Empire during its nascent stages. However, he eventually transitioned to independent operations in the vicinity of the planet Majoor. He and his crew attained celebrity status, inspiring the creation of the audio drama, Space Pirates of the Galaxy. During this period, the Majooran authorities took Reddjak into custody.
A youthful Majooran named Llez, a dedicated fan of the fictional Reddjak depicted in Space Pirates of the Galaxy, decided to liberate the pirate and become part of the Red Fury Brotherhood. After posing several pointed questions to the boy, Reddjak discovered that a peace convoy led by Ambassador Zell would be traversing the system, identifying it as a prime target for an assault. Nevertheless, C-3PO and R2-D2 thwarted his plans, successfully preventing the attack, assisting Ambassador Zell in capturing Reddjak, and rescuing his son, Llez.
Reddjak and his crew, known as the Red Fury Brotherhood, emulated the rogues and outlaws featured in holodrama. Adopting all the stereotypical characteristics of their archetype, the crew consisted of diverse aliens hailing from various corners of the galaxy. One of their initial schemes involved seizing and commandeering the Galactic Republic diplomatic cruiser, the Dura-Khan III. Subsequently, the ship was renamed Blood Brother and extensively modified for pirate activities. Reddjak possessed unwavering confidence in his leadership abilities, further bolstered by Inquisitor Valin Draco, who recruited the captain's services in the months following the establishment of the New Order.
Reddjak's new role within the Galactic Empire required him to patrol the airspace above Almas, situated in the Cularin system. This was to ensure Draco's undisturbed search for a Sith holocron within the ruins of the destroyed Almas Academy. During this period, the Red Fury Brotherhood rose to prominence as the most formidable piracy organization operating in the Cularin system. Reddjak, intending to plunder the Empire's adversaries should they venture near Almas, concealed the Blood Brother behind the moon Dorumaa. When a group of operatives aligned with the fugitive Jedi Master Denia entered the system, Reddjak ambushed them, demanding their surrender for boarding. However, they resisted and managed to overcome the Red Fury Brotherhood. Having failed in his mission for the Empire, Reddjak and the Brotherhood resumed their pirate lifestyle.
During the Imperial Period, Reddjak's notoriety grew to such an extent that he achieved a form of celebrity. He served as the inspiration for the "Crimson Pirate" character featured in the fictional audio program, Space Pirates of the Galaxy, although the children comprising the target demographic remained unaware of his real existence. Despite this, posters depicting Reddjak's likeness adorned the walls of children aspiring to join his crew of cutthroats.

Eventually, the Majooran authorities apprehended and imprisoned Reddjak. He was transported to Majoor, but as he was being escorted to prison, a young Majooran named Llez destroyed his droid escort. Llez, a devotee of Reddjak's fictional adventures, rescued the criminal by employing a magno-neutralizer on the escort droids and assisting him in hijacking the Majooran guard ship. Reddjak never learned the youngster's real name, as he preferred to be called the "Scarlet Pirate."
During his interrogation of the "Scarlet Pirate," Reddjak discovered that the boy's father was Ambassador Zell, and that the ambassador had recently embarked on a peace mission. Reddjak recognized that this implied a lightly escorted convoy would be passing through the area, presenting a lucrative opportunity for him and his crew, although he concealed his intentions from the child. After rendezvousing with his ship, Reddjak introduced the "Scarlet Pirate" to his crew before rushing to the control room. Ordering his crew to locate and destroy Zell's peace convoy, Reddjak was confronted by Llez, who felt betrayed by the pirate.

Growing weary of Llez's objections, Reddjak struck the boy and instructed nearby droids to confine him. Unbeknownst to Reddjak, the droids were R2-D2 and C-3PO, Llez's caretakers, who had secretly boarded the guard ship. As the pirate ship approached within range, Reddjak ordered his crew to launch plasma torpedoes at the convoy, but the projectiles mysteriously detonated before reaching their targets. Demanding an explanation for the malfunction, Reddjak was informed that the abort command originated from the ship's weapons room. Enraged, the pirate led his band of cutthroats to the room, intending to apprehend the traitors in the act. Unbeknownst to Reddjak, Llez had managed to alert Zell to his presence on the pirate ship.
Upon cornering the culprits, Llez, C-3PO, and R2-D2, the Captain prepared to impale the Majooran with his vibrorapier. Before he could act, the child hurled his club at Reddjak, momentarily incapacitating him. Although R2-D2 attempted to defend against the other pirates, Reddjak managed to seize Llez, holding the Majooran at his mercy. Before the pirate could exploit his hostage for leverage, Ambassador Zell, who had secretly boarded the ship, held Reddjak at gunpoint and demanded custody of his son. Feigning surrender, Reddjak released Llez before swiftly retrieving his vibrorapier. As he prepared to behead Zell, C-3PO warned the ambassador of the danger, allowing him to seize Llez's club and strike the pirate with it. Once again, Reddjak found himself under arrest as Zell's guards secured the ship.

Reddjak possessed a flamboyant demeanor, sporting the archetypal attire of a holodrama buccaneer—a crimson blouse, unbuttoned to the waist and secured with a gold sash—and a pencil-thin mustache reminiscent of many fictional villains. Reddjak bore a Human-like appearance, albeit with pointed ears and four-fingered hands. He exhibited unwavering confidence in his abilities, yet his impatience occasionally cost him success. His overconfidence also rendered him vulnerable to others, often compounded by his cruelty and lack of hesitation in harming those weaker than himself. Reddjak and his crew displayed utter disregard for innocent lives, readily attacking unarmed diplomatic vessels.
David Manak conceived Captain Reddjak, who made his debut in 1986's Droids (1986) 3. Reddjak remained unused in Star Wars Legends for over two decades, until Abel G. Peña incorporated him as a character in the 2008 roleplaying adventure Echoes of the Jedi. Peña selected Reddjak over another red-themed pirate, Crimson Jack, because Crimson Jack had already featured in a greater number of stories than Reddjak.