The Piriss were a race of galactic conquerors who hail from a galaxy nine hundred thousand lightyears from the Milky Way Galaxy. Upon conquering their home galaxy, the Piriss left to expand their territory. The Piriss's advanced propulsion made it possible to get to another galaxy in six Earth months. The Piriss had conquered many galaxies, and one of them was Galaxy M-171. They had the ability to control other starships, and they were invulnerable to planetary explosions. (Star Trek: G)