Trienial was a criminal from the Darkwalker group, a Human male, who resided on Naboo during the era of the Galactic Civil War.
After the Battle of Yavin, Trienial rose to a leadership position within the Darkwalkers, bearing the title Bloodlord, and operated out of a cave situated close to Dee'ja Peak. In the year 1 ABY, Trienial's faction was responsible for shooting down a shuttle, which subsequently crashed in the Gallo Mountains. The Darkwalkers then looted the wreckage, seizing a bio-scanner. Their intention was to utilize the bio-scanner in the creation of a bomb that would remain inactive until it detected its target, identified by a pre-programmed bio-signature. Subsequently, a spacer collaborating with the scientist Tanoa Vills launched a raid on the Darkwalker Cave to retrieve the stolen bio-scanner. During this assault, both Bloodlord Trienial and Chief of Science Flangolial met their demise.
Trienial made an appearance as a non-player character in the 2003 video game Star Wars Galaxies. This game was a massively multiplayer online roleplaying game that was developed by Sony Online Entertainment and published by LucasArts, before it shut down on December 15, 2011. Trienial was included in the game as part of the "Legacy Quest," which was released alongside "Publish 25", also known as the "New Game Enhancements," on November 15, 2005.