Serj Ukkarian, a human child during the High Republic, found himself aboard the transport vessel Legacy Run. This starship carried thousands of colonists bound for the Outer Rim. Traveling with his mother and father, Ukkarian drew the ire of Commander Hedda Casset after his attempt to infiltrate the vessel's data stores for mature content. In response, he tried to hack the control deck. This act placed him in a position to witness the near-catastrophic event that destroyed the Legacy Run during the Hyperspace Disaster. He survived this disaster due to being within a sealed section of the ship. Later, while recuperating on the Republic hospital ship Panacea, Jedi in training Burryaga Agaburry offered him comfort, and learned about what he had seen, despite the communication barrier of language. He then convinced the boy to share the information with his Jedi Master Nib Assek.
Serj Ukkarian, a human boy, was born circa 242 BBY. Around the age of ten standard years old, in 232 BBY, he boarded the Byne Guild transport Legacy Run with his parents. They were among the many colonists traveling from the Core and Colonies to settle in the Outer Rim. During the voyage, the ship's master, Hedda Casset, became aware of Serj, and he made friends with other children on board.
During the trip, Ukkarian and his companions had viewed all the appropriate holograms in the Legacy Run's archives. Serj then attempted to hack into the ship's systems to view restricted content. He encountered Captain Casset in the common area during her evening rounds. He asked her for more media, but Casset, aware of his hacking attempts, scolded him and warned him that she was aware of everything happening on her ship. Ashamed, Ukkarian and his friends went back to playing a makeshift game of ball as Casset departed.
Ukkarian, feeling humiliated by the scolding, decided to get back at Casset. His plan was to hack into the bridge computers and display a holovid on the screens, proving Casset wrong about her knowledge. He went to compartment eight to carry out his plan. He succeeded, but just as he gained access, the Legacy Run collided with an anomaly in hyperspace, an event that should have been impossible. Ukkarian saw the obstacle as three lightning strikes, as Casset tried to navigate the vessel around it. However, the Legacy Run was torn apart by the stress, and Casset only had time to seal the passenger sections before her passing. Ukkarian's section survived, but his parents were in section twelve, leaving his parent's fate unknown.
The resulting Hyperspace Disaster threatened the Hetzal system, as debris was ejected from hyperspace on collision courses. This included ten passenger sections. The Jedi and Republic managed to secure the system and all the ejected passenger sections, including number eight. The survivors were then housed on the Republic medical vessel Panacea. Ukkarian, traumatized, blamed himself for the incident and refused to respond to therapy droids.
During recurring Emergences of the disaster, a reception was held on the Panacea, stationed in the Hetzal system. This allowed patients to thank the Jedi and Republic personnel involved in their rescue. During the reception, Jedi trainee Burryaga Agaburry, the Jedi who first realized there were people on the debris, noticed Ukkarian. Realizing the child was in emotional distress, Burryaga connected with Ukkarian despite the language barrier. As a Wookiee, Burryaga could not speak Basic, and Serj did not understand Shyriiwook. Ukkarian confessed to Burryaga that he had hacked the Legacy Run's bridge and seen something related to the disaster's cause. Burryaga brought Serj to his Master, Jedi Nib Assek, who coaxed the boy into revealing that he had seen three lightning strikes. After recovering the Legacy Run's black box during the 40th Emergence, the Jedi and Republic learned that Ukkarian had seen a Nihil Stormship.
Serj Ukkarian was a human boy with red hair and olive complexion. Naturally mischievous, he was bright and sociable, but disliked being reprimanded. As a result, he attempted to get back at Captain Casset after being scolded for trying to watch restricted holograms, believing she was not as knowledgeable as she seemed. The presumed loss of his parents in the Great Disaster deeply affected Ukkarian, and he felt responsible for the incident due to his actions of hacking the bridge systems. He could understand Burryaga Agaburry's nonverbal communication despite not understanding his words.
Serj Ukkarian debuted in the 2021 novel The High Republic: Light of the Jedi.