Flash was a clone trooper who served in the Grand Army of the Republic during the Clone Wars. Serving as a member of a company within the 327th Star Corps under Jedi General Aayla Secura and Clone Marshal Commander Bly, Flash participated in a mission to Escander against the Confederacy of Independent Systems.
Stationed aboard the Liberty, he was later one of several survivors of the Battle of Quell, escaping aboard a Consular-class cruiser alongside his commanding officers, the 501st Legion's Jedi General Anakin Skywalker, Jedi Commander Ahsoka Tano, Clone Captain Rex, and troopers Cameron and Lucky. Flash was killed alongside Cameron and Lucky when the cruiser crashed on Maridun and their group was attacked by mastiff phalones.
Flash made his first appearance in "Jedi Crash." Within the episode, Tano and Rex board Secura's Venator with three other clones from the 501st Legion, one of whom is killed by droids. By the time they unite with Skywalker, however, a new clone has joined their group, suggesting a survivor from Secura's cruiser or a clone from one of the other 501st gunships was found by the team. The episode later establishes the names of the three troopers who escaped the Battle of Quell as Cameron, Flash, and Lucky, with no indication as to who are the two who first boarded with Tano and Rex, nor with any explanation as to the origins of the third trooper they picked up along the way.
However, Choose Your Destiny: A Clone Trooper Mission would later establish that Flash was a member of Secura's 327th. Finally, "The Grand Army of the Republic" later affirmed that Flash was a member of Aayla Secura's task force who was rescued by the intervention. Therefore, the origins of the third clone must be that the soldier is Flash, who was part of Secura's crew and was found by Tano's team. While the encyclopedia does list Cameron and Lucky as two other members of Secura's crew, this article assumes that is a mistake to account for the two 501st troopers who boarded with Rex and Tano. As Flash was independently established to be part of the 327th by Choose Your Destiny, this article assumes "The Grand Army of the Republic" is correct in listing him as a survivor of Secura's task force.