Trienial was a Human male Darkwalker criminal who lived on Naboo during the time of the Galactic Civil War.
Following the Battle of Yavin, Trienial was a leader of the Darkwalkers, holding the title of Bloodlord, who operated from a cave near Dee'ja Peak. In 1 ABY, Trienial's group shot down a shuttle that crashed in the Gallo Mountains. The Darkwalkers plundered the wreckage and stole a bio-scanner. Their objective was to use the bio-scanner to make a bomb that would remain inert until its target with the programmed bio-signature came nearby. A spacer working with the scientist Tanoa Vills then raided the Darkwalker Cave to recover the stolen bio-scanner. Bloodlord Trienial and Chief of Science Flangolial were both killed during the assault.
Trienial appeared as a non-player character in the 2003 video game Star Wars Galaxies, a massively multiplayer online roleplaying game developed by Sony Online Entertainment and published by LucasArts, prior its closure on December 15, 2011. Trienial was added to the game as part of the "Legacy Quest," released with the "Publish 25", a.k.a. the "New Game Enhancements," on November 15, 2005.