GT-643 was a male Human character from the Legends continuity who served the Galactic Empire as a stormtrooper throughout the Galactic Civil War.
Following the Battle of Yavin, GT-643, along with his fellow stormtroopers KD-121 and HX-138, found himself stationed at the Imperial Research and Prison Facility located on the planet Dathomir.
In the year 1 ABY, an accident occurred at the Imperial Research and Prison Facility. The Blackwing virus, under study at the facility, broke free of its containment, resulting in the decimation of most of the local population. Those infected were transformed into ravenous undead creatures. In response to this catastrophe, the Galactic Empire quickly established a Quarantine Zone in an attempt to control the spread of the infection. GT-643, along with KD-121 and HX-138, were among a group of stormtroopers who appeared to possess immunity to the virus. They managed to survive the initial outbreak, but found themselves trapped within the Quarantine Zone alongside other survivors. These stormtroopers, together with the other refugees, established a provisional settlement known as Camp Epsilon, with the goal of fending off the relentless zombie attacks and seeking safety while awaiting potential evacuation. These survivors included Zsu Val, a former prisoner; Sogan Varga, a technician; Nils Cridmeen, a mechanic; and Klex Fulgor, an Inquisitor. Despite its purpose, Camp Epsilon was a dangerous place, situated in the courtyard of the Imperial Research and Prison Facility, the epicenter of the undead activity. However, the camp's location was chosen due to the presence of a Lambda-class shuttle, the only remaining starship in the area that had survived the outbreak. Although damaged and grounded, Nils Cridmeen and the stormtroopers hoped to repair the ship, providing a means for the survivors to escape the Quarantine Zone.
During their travels within the Quarantine Zone, a group of spacers made their way to Camp Epsilon. They provided assistance to the stormtroopers by rescuing some survivors and procuring parts needed for the shuttle's repair. Subsequently, the spacers departed Camp Epsilon, venturing into the Imperial Research and Prison Facility to retrieve a sample of the Blackwing virus. After successfully completing their mission, the spacers returned to Camp Epsilon. In the intervening time, Nils Cridmeen had managed to repair the Lambda-class shuttle. Ultimately, the refugees of Camp Epsilon, along with the spacers, successfully escaped the Quarantine Zone aboard the repaired shuttle.
GT-643 appeared as a non-player character within the 2003 video game Star Wars Galaxies. This massively multiplayer online roleplaying game was developed by Sony Online Entertainment and published by LucasArts before its closure on December 15, 2011. GT-643 was introduced into the game through "Game Update 14," also known as the "Death Troopers" update, which was released on October 12, 2009.