The Ssi-ruuk were an alien species that equally matched the Yuuzhan Vong. The Ssi-ruuk tried to take over the galaxy by first attacking the planet of Bakura, and defeating the Imperial garrison, but the Imperials, with the help of the Rebel Fleet, took back the planet and later betrayed the Rebels. Later, the Ssi-ruuk joined the Yuuzhan Vong Invasion on the New Republic side and massacred a massive number of Yuuzhan Vong forces. Later, they were allied with the New Galactic Empire and the Malfoy Cartel during the Fourth Yuuzhan Vong Invasion.