During the latter years of the Galactic Republic, a male Yinchorri was convicted for murdering six other members of his species. After the Muun Sith Lord Darth Plagueis helped the Yinchorri to gain representation in the Galactic Senate, the Yinchorri Council of Elders gave the criminal to Plagueis, as a gift. The Sith Lord imprisoned the Yinchorri on the planet Muunilinst and there, he performed a number of experiments on the murderer, in an attempt to learn more about the natural resistance to Force persuasion that all Yinchorri possessed. After two years of testing, Plagueis eventually developed a method by which he could bypass the murderer's Force-resistance and compel the Yinchorri to become placid.
- Darth Plagueis (First appearance)