Ulldin was a male Human Jedi Knight who served The Galactic Republic during the Cold War. He was an ally of Jedi Master Nomen Karr while he and his Padawan were being hunted by Sith forces of Darth Baras. He and Jedi Knight Zylixx were dispatched to a ship in the Outer Rim to stop a Sith apprentice who was later confirmed as the hunter for the two Jedi. Ulldin and Zylixx confronted the Sith, but it is unconfirmed as to how any conflict resulted. Some reports suggest that he fought with Zylixx when the other Knight was goaded into a rash attack, whilst others suggest that the Sith talked him out of the fight and left Zylixx to his fate.