A former captain in the Klingon Defense Force, Korris became disillusioned with the attitude of peace within the Klingon Empire. He and his comrades Kunivas and Konmel decided to hijack the Batris - a Talarian freighter - in order to find a planet where they could live as warriors. The Klingons sent the IKS T'Acog to bring back the renegades, but they were able to destroy the cruiser despite their freighter's meager defenses.
The Batris was later discovered near the Romulan Neutral Zone by the USS Enterprise-D and Korris and his fellows were rescued (though Kunivas died from his injuries). After meeting Lt. Worf, Korris and Konmel attempted to sway him to their way of thinking, hoping he would join them. Worf was not convinced and when the truth came to light about Korris's actions prior to his rescue, he and Konmel were arrested and held in the ship's brig.
When another Klingon ship arrived to take custody of the renegades, Korris and Konmel attempted to escape. Konmel was killed but Korris made it to the Enterprise's Engineering section and threatened to blast the warp core with a phaser. Worf confronted Korris in Engineering and managed to shoot the crazed Klingon with his phaser. Worf then glared into Korris's eyes as the life slipped away from him, howling loudly as per the Klingons' traditional death ritual.