S'itl Thirr was a male Abinyshi, short, thin, and reptilian like other members of his species. During the Galactic Civil War, Thirr visited the office of the Iyra sentientologist Tem Eliss in the University of Sanbra's Sentient Studies Department in an effort to dispel misinformation that the Galactic Empire had spread about the supposed extinction of the Abinyshi species. There, the professor was working on a publication known as The University of Sanbra Guide to Intelligent Life. After Thirr granted an interview to the Iyra and explained his species' true predicament, the scientist added an entry on the Abinyshi to his Guide that told Thirr's version of the species' story.