A member of the Yresilini species became a general under the tutelage of Chiss pupil Sev'rance Tann around 22 BBY. This training was undertaken because Tann was tasked by a professor from the Chiss Academy to transform a group of Yresilini into a functional army, despite the widely held belief that the species' were incapable of being trained. Tann initiated the process by selecting a Yresilini to serve as a general, providing him with simple orders that were met with ridicule by the general and the other Yresilini. In response, Tann had the first general executed publicly, before selecting a successor who followed her orders without question, thereby leading the other Yresilini to do the same.
The existence of this Yresilini general was first revealed within Sev'rance Tann's information file in the 2002 video game Star Wars: Galactic Battlegrounds: Clone Campaigns, created by LucasArts.