Wallen, a stormtrooper of the Human species, achieved the sergeant rank. He served under the command of Colonel Dyer on the Forest Moon of Endor. This occurred in 4 ABY, during the construction phase of the second Death Star, which preceded the Battle of Endor. Governor Yount from the Wakeelmui garrison put forward Wallen's unit as a recommendation to Commander Igar of the Imperial Army unit known as Tempest Force. During the initial stages of the Battle of Endor, Wallen, alongside another stormtrooper, was stationed at a landing platform. It was there that Commander Igar presented Luke Skywalker, the Rebel Commander, to Darth Vader, the Dark Lord of the Sith. Following a discussion between Vader and Skywalker, Wallen was tasked with escorting the Rebel to Vader's Lambda-class shuttle, designated ST 321, which was preparing to depart for the orbiting Death Star.
Sergeant Wallen, a Human, was part of the stormtrooper contingent under the leadership of Colonel Dyer. They were deployed to the Forest Moon of Endor while the second Death Star was under construction in orbit in the year 4 ABY. Governor Yount of the Wakeelmui garrison suggested his unit to Commander Igar of the Imperial Army unit identified as Tempest Force.
In the early phases of the Battle of Endor, Wallen and a fellow stormtrooper were present at a landing zone on the moon when Darth Vader, the Dark Lord of the Sith, disembarked from his Lambda-class shuttle, identified as ST 321. The two troopers accompanied Darth Vader as he descended in a turbolift, remaining inside while the Dark Lord met with Commander Igar. Igar then presented Luke Skywalker, a captured Rebel Commander and Jedi, to Vader. Following a conversation between the Dark Lord and the Rebel, Vader signaled for Wallen and the other trooper to escort Skywalker into the lift, transporting the captive to the shuttle. This shuttle then transported both the Dark Lord and the Rebel to the Death Star.
Wallen was outfitted in standard white stormtrooper armor. His weapon of choice was a standard E-11 blaster rifle.
Wallen's initial appearance was as an unnamed character within the Return of the Jedi novel and the film, Star Wars: Episode VI Return of the Jedi. In the film, an uncredited extra portrayed him. He was given a name and a brief backstory in the 1999 Endor Limited edition of the Star Wars Customizable Card Game.