DJ-88, also known as Dee-Jay, was a droid of the third degree who was associated with the bygone Jedi Order. DJ-88, a white, humanoid robot with red photoreceptors, was created by its Jedi master to safeguard the Lost City of the Jedi, a hidden library and terraforming base situated far beneath Yavin 4's surface.
DJ-88 became the tutor of the infant Ken when he was brought to the Lost City by a Jedi Master in brown robes. Until Ken met Luke Skywalker and became the youngest member of the Alliance to Restore the Republic in 5 ABY, the ancient droid served as a father figure to the young Jedi Prince.
The year that DJ-88's existence ended was the same year that the pseudo-Kadann, an operative of the Galactic Empire masquerading as the Supreme Prophet of the Dark Side, attacked the Lost City and gave the order to deactivate the antiquated droid.
Following the conclusion of the Great Sith War, the fourth moon of Yavin Prime displayed the marks of a devastating orbital assault by the Jedi Order. The Jedi, aiming to repair the damage inflicted on Yavin 4's environment, established an underground city designed to restore the moon's ecosystem. After all the Jedi Knights had permanently departed from the city, the library and weather station were entrusted to the diligent care of droids. This location, now known as the Lost City of the Jedi, was entirely managed by artificial intelligence for thousands of years, with older droids constructing newer models as they aged.
DJ-88, already ancient but powerful, was in charge of the Lost City of the Jedi a few years before the Galactic Civil War broke out, serving as both caretaker and instructor. At some point, a Jedi Master whose identity remains unknown arrived on Yavin's fourth moon, concealing himself behind brown robes, bringing the infant Ken with him. Ken was the baby son of Triclops, Emperor Palpatine's own offspring, and the Jedi Princess Kendalina, who had been murdered by the Galactic Empire. DJ-88 was directed to nurture and educate Ken. The chief caretaker droid carried out his mission diligently, teaching the young boy about ecology, astronomy, computers, and approximately fifteen other subjects.
DJ-88 dedicated around twelve years to educating and safeguarding Ken to the best of his abilities, hoping that the boy's Jedi lineage would triumph over the dark side that was also inherent in him. The white droid made the decision not to reveal the terrible truth to his pupil, as knowing he was the grandson of Emperor Palpatine would have caused him irreparable harm. The details of Ken's origins had to remain concealed until the prince matured into a grown man—old enough to confront the truth.
DJ-88's protégé broke the rules in 5 BBY and ventured to the moon's surface. Ken was discovered by the droid conversing with Luke Skywalker, a modern-day Jedi and a hero of the Rebel Alliance. DJ-88 was aware of Skywalker, but he did not immediately agree to allow Ken to accompany him, despite the boy's enthusiasm to join the Alliance. The caretaker robot raised his hands and released a blinding smoke into the air, allowing him to return the Prince to the city undetected. Ken once more escaped some time later, arriving on the Topworld during an Imperial attack that was setting the forests ablaze. DJ-88 came to his pupil's rescue and ran into the Rebellion's heroes. Skywalker and DJ-88, now properly acquainted, decided to collaborate in order to put out the fires. The old droid admitted that it was time for Ken to explore the larger galaxy after the battle was over, and he permitted Luke Skywalker to take the child with him.
However, while on a quest in the mushroom forests of Arzid, stormtroopers captured Skywalker and Ken. They were delivered to the members of the Church of the Dark Side, a fictitious religion made up of the Prophets of the Dark Side. Their leader, a Bimm impersonator posing as the Supreme Prophet Kadann, intended to steal the ancient Jedi knowledge contained in the Lost City's library and enticed the young Jedi Prince into revealing the location of the Lost City of the Jedi. Ken, eager to learn about his origins, betrayed his city and brought the Prophets to it. DJ-88 questioned Ken about the motivation for his betrayal when he saw the Imperials storming the library. As everything appeared to be lost, the caretaker droid made the decision to reveal the truth. DJ-88 went into great detail about the Jedi Prince's terrifying origin story. Ken, unwilling to believe it, started to cry and pounded on Dee-Jay's chest. The Kadann impersonator then gave the order to deactivate the caretaker droid as the old droid attempted to comfort his pupil. An Imperial agent acted quickly, opening a panel in the old droid's back and turning him off. DJ-88 remained silent and unmoving.
DJ-88, a third-degree droid, was a member of the most sophisticated class of droids ever created. The caretaker was a towering robot with white plating that, from a distance, resembled a stormtrooper. It had a commanding, dignified face with a metallic beard-like appendage and brilliant red photoreceptors that shone like rubies. DJ-88 lacked any offensive capabilities, but he was able to lift his hands and produce a thick white smoke from his fingertips. This blinding mist served as a defensive measure against adversaries and as a screening device to conceal the droid's movements.