Yelkin, a male Devaronian, made his living as both a thorilide miner and a pilot on the moon of Cynda. His time there occurred during the early years of the Galactic Empire's reign. He was an employee of Moonglow Polychemical, working as part of Okadiah Garson's human team, where he drilled holes for explosive placement. During a cave-in on Cynda, Yelkin was rescued by Kanan Jarrus, a Jedi who had survived the Purge; however, Yelkin subsequently died in an explosion that took place on the moon.
During the Age of the Empire, Yelkin, a Devaronian, worked as a miner and pilot within the Gorse system. Back in 11 BBY, Yelkin was the one piloting a personnel transport, its purpose to carry miners to the mining moon called Cynda. Regrettably, he approached the landing bay at too great a speed, resulting in his freighter scraping against the doorway's side. Consequently, the mining vessel was rendered inoperable and was left partially sticking out of the landing bay. Shortly after this, a Moonglow Polychemical-owned freighter hauler, known as the Expedient, flew into the landing bay entrance, barely avoiding contact with Yelkin's transport. This reckless action by freighter pilot Kanan Jarrus left Yelkin and the other miners both shaken and furious.
Yelkin, incensed by Kanan's recklessness, confronted the young human pilot after he had completed his landing. When Kanan chose to ignore him, Yelkin then grabbed Kanan by the shoulder. Reacting with his Force-enhanced reflexes, the survivor of the Great Jedi Purge spun around swiftly and twisted Yelkin's arm. Kanan pointed out that his ship was obstructing the way, to which Yelkin retorted that everyone faced deadlines, especially since the Galactic Empire had destroyed the freighter Cynda Dreaming for being too slow. Kanan then told him to increase his speed, but not to be reckless. Several miners then stepped up to defend Yelkin, voicing their criticism of Kanan's dangerous piloting.
Okadiah Garson, a friend of Kanan's who ran a cantina named The Asteroid Field on the planet Gorse, managed to defuse the situation by inviting the miners, Yelkin included, to his cantina for drinks after their shift. Despite Yelkin's initial anger towards Okadiah for associating with "some real pieces of work", he was appeased by Okadiah's offer and proceeded to work without further issue with Kanan. Yelkin and his fellow miners then headed to Zone Forty-Two, where they commenced preparations for a blasting operation. They were eventually joined by Kanan, who arrived with a hovercart carrying baradium bisulfate. It was at this point that one of the miners discovered that Skelly, a dissident miner, had planted explosives at the site, intending to highlight the dangers of mining on Cynda to both the Empire and the mining companies.
Unable to disarm Skelly's bomb, Yelkin and Kanan were compelled to escape. During their flight from the explosion, Yelkin twisted his ankle, and then he warned Kanan to secure his load of explosives to prevent further complications. Despite their initial hostility, Kanan successfully rescued the Devaronian, lifting him onto his hovercart before driving them out of the blast zone. After escaping through a tunnel, Kanan pushed Yelkin forward, secretly using the Force in the darkness to prevent being crushed. After their escape from Zone Forty-Two, Kanan left the injured Yelkin in the care of Okadiah and the rest of the mining team. Skelly's illegal explosion coincided with a visit from Count Denetrius Vidian, an Imperial efficiency expert, who had arrived to boost production in the Gorse system.
Two days later, Yelkin and Okadiah were among the miners who perished when Count Vidian conducted a test bombing in Cynda's Zone Sixty-Six. Vidian had decided to detonate Cynda under the guise of improving thorilide mining productivity within the Gorse system. To alleviate concerns from his Imperial superiors that detonating Cynda would harm the thorilide crystals, Vidian orchestrated a test bombing and manipulated the results to support his plan. Yelkin's body was crushed by the explosion and became embedded within the moon's new strata. His remains were discovered by Kanan and his new rebel ally Hera Syndulla, who had traveled to the moon to rescue Okadiah after learning about the test bombing.
Yelkin, being a Devaronian, was characterized by the presence of horns on his head. He also possessed a reputation for having a short fuse, which led him to confront Kanan Jarrus after the latter executed a risky maneuver by piloting his freighter past Yelkin's damaged vessel. Although Yelkin was capable of piloting a starship, his piloting skills were not particularly refined, as evidenced by his crash into the doorway, causing a traffic jam. While Yelkin was physically strong, he was unable to compete with the Force-enhanced reflexes of Kanan, who was secretly a Jedi Purge survivor. As a miner, Yelkin possessed considerable expertise in handling explosives and understood how to accurately measure the depth of a borehole. Despite their initial conflict, Kanan held Yelkin's life in enough regard to save him from being killed by an explosion.
Yelkin's initial appearance was as a minor supporting character in John Jackson Miller's 2014 novel, A New Dawn, which served as the inaugural book in a new series of Canon novels produced with the collaboration of the Lucasfilm Story Group. Most of his dialogue and interactions are presented through the perspective of Kanan Jarrus, one of the novel's primary characters who later starred in the Disney XD television show, Star Wars Rebels.