As a representative of the planet Krystar, Vishar Koss, an Ovissian, served in the Galactic Republic during the Clone Wars. She contacted her friend, Senator Padmé Amidala, after discovering that Queb, the planet's regent, had built a compound to house clone trooper prisoners captured by the Confederacy of Independent Systems. Subsequently, Amidala, accompanied by Jedi General Obi-Wan Kenobi and his troopers, embarked on a mission to Krystar. During this mission, Koss and Amidala uncovered Queb's plan to sell the clones to the Trandoshans.
During the era of the Clone Wars, Vishar Koss, an Ovissian, held the position of representative for her homeworld of Krystar, a planet aligned with the Galactic Republic. She maintained a long-standing friendship with Padmé Amidala, who was the Republic senator representing Naboo. In the year 22 BBY, Koss became aware that the Confederacy of Independent Systems was transporting captured clone troopers to Krystar. These troopers were being held in a secret compound recently constructed near the Krystar palace by the local regent, Queb. Due to her apprehension about confronting the regent, Koss chose not to conduct her own investigation. Instead, she relayed this crucial information to Amidala. In response, the senator initiated a mission, traveling alongside Jedi General Obi-Wan Kenobi and a contingent of his forces.
Under the pretense of a diplomatic visit, Amidala and Kenobi arrived on Krystar, where they were greeted with suspicion by Regent Queb, who had not approved such a visit. Koss intervened, explaining that she had invited the senator to look into agricultural issues on Krystar, thereby covering for Amidala. Queb reluctantly permitted Amidala to remain but insisted she stay within the palace. After the regent's departure, Amidala inquired about Queb's typical demeanor, to which Koss confirmed his usual disagreeableness. This ruse provided time for Kenobi's troopers to conduct reconnaissance on the compound, verifying that it served as a prison for clones and that Queb was collaborating with Separatist forces. Simultaneously, Koss accompanied Amidala as she secretly observed Queb, discovering that the regent had been selling the prisoners to a Trandoshan for the purpose of being hunted. Upon learning this, Amidala informed Kenobi, who then ordered his troopers to raid the compound and liberate the prisoners.
Upon discovering the prisoners' escape, the Trandoshan confronted Queb, who then accused Amidala. The senator advised Koss to proceed to her Eta-class shuttle, but the Trandoshan attempted to attack them. Kenobi emerged from the shuttle and used the Force to pushed the Trandoshan away, allowing Koss and Amidala to board the starship. As the shuttle left Krystar, Koss expressed her concern about being unable to return home with the regent still in power. However, Kenobi assured her that additional Republic forces were en route to apprehend Queb. Aboard the ship, Koss witnessed Kenobi's pledge to prevent the clones from being treated as expendable and his commitment to fighting for all of the Republic's allies in the conflict. Later that year, Clone Commander Cody and Boil recounted the events that transpired on Krystar to their fellow Commander Wolffe during a battle on the planet of Hisseen.
Vishar Koss's reluctance to independently investigate the Separatist presence on Krystar stemmed from her fear of Regent Queb. She also worried about the possibility of being unable to return home after exposing his actions. Nevertheless, she felt comfortable sharing her genuine opinions about Queb with Senator Amidala, a close friend in whose abilities and influence within the Galactic Senate Koss had great confidence. This Ovissian was characterized by her green skin, long red hair, and black eyes.
Vishar Koss made her debut in the third issue of the Star Wars Adventures: The Clone Wars – Battle Tales comic series. This issue, penned by Michael Moreci and released on August 5, 2020 by IDW Publishing, featured a flashback story with illustrations by Valentina Pinto.