Viggen was a male human who served in the military of the Galactic Empire. In the fourth year before the Battle of Yavin, he served as the commanding officer of an Imperial base on Imvur. Under his watch, the base was raided by a group of anti-Empire insurgents led by Commander Ryden. Although Viggen's men damaged their transport starship, the rebels still managed to escape with stolen supplies. Intent on wiping out Ryden's operations, the Imperial C.O. then tracked the insurgents to their base, which was also located on Imvur. Once he arrived in the orbit of Imvur aboard an Imperial I-class , Viggen was glad to find the rebels unprepared to evacuate. Against the suggestion of a lieutenant, the C.O. chose to launch an immediate ground assault instead of starting with an orbital bombardment. Having taken place in one of two AT-AT walkers, Viggen led his war machines toward Ryden's base, easily breaking through the rebels' meager defenses.
At one point, the rebels apparently decided to counter-attack, as three MLC-3 light tanks came out of the base and fired on the AT-ATs. Convinced that those obsolete tanks were no match for his walkers, Viggen continued on to his primary target, ignoring the MLC-3s. He quickly changed his mind when one of the tank, piloted by the rebel Kanan Jarrus, managed to destroy an AT-AT by hitting its neck at full power. The Imperial then figured out the tanks were only performing distraction maneuvers. When Ryden was forced to exit his tank, Viggen ordered his men to shoot him. That action, however, was interrupted by the sudden arrival of a rebel evac ship that brought the remaining AT-AT down. Although Viggen and the pilots survived the crash of their walker, they were forced to watch the rebels flying away from Imvur.
During the reign of the Galactic Empire, Viggen served as the commanding officer of an Imperial base and also controlled his own Imperial I-class . In 4 BBY, his base was by a rebel cell led by Commander Ryden. The rebels managed to successfully steal a large amount of supplies during the raid, but their transport was heavily damaged and of them was captured by the Imperials before the rest escaped.
Angered at the trouble Ryden and his men had caused him, Viggen traveled on his Star Destroyer to locate the rebels' base, which was also located on Imvur. The rebels became aware of his coming after they intercepted a transmission he sent out. Upon reaching orbit, one of the vessel's lieutenants informed Viggen that they had arrived, and wanting to see to the end of the cell personally, Viggen declared that he would lead Imperial forces on the planet's surface to destroy the base and threatened to demote the lieutenant when he questioned the sense of such a decision by suggesting an orbital bombardment instead. Word was then sent to Viggen's men to prepare for an assault, and two All Terrain Armored Transports were deployed to the surface of Imvur, one of which carried Viggen on board.
As the two walkers made their way through a canyon toward the base they triggered the rebel's outer perimeter alarm and were quickly spotted by a lookout post that managed to send imagery of Viggen's forces back to Ryden at the base before being destroyed by the Imperials. Turrets on the walls of the canyon then began firing on the walkers, but their weaponry was not strong enough to pierce the vehicle's armor and so Viggen had his forces carry on unperturbed, destroying the rebel defenses in sectors three and four as they did. The AT-AT's sensors then picked up three approaching targets; a trio of MLC-3 light tanks piloted by Ryden himself and two members of a separate rebel cell providing aid to Ryden's: the former clone trooper Rex and the Jedi Kanan Jarrus, both of whom had prior experience in facing All Terrain Armored Transports.
Believing that the tanks were a desperate ploy by the rebels which would still not be able to damage the walkers, Viggen orders his AT-AT pilots to ignore the distraction tactics the tanks were employing and continue on toward the base. He swiftly changed his tune however when the rebel's astromech droid C1-10P piloted the VCX-series auxiliary starfighter Phantom into the canyon and opened fire on the second walker's neck, weakening it enough to allow Jarrus to fire with his tank and destroy the walker. Realizing that his walkers were not as invulnerable as he had believed, Viggen ordered that the tanks be destroyed, and Jarrus only narrowly dodged a gruesome death as he abandoned his tank before it was crushed by one of the AT-AT's huge feet.
Having figured out the rebels tactics, the Imperials managed to prevent the Phantom from getting a clear shot on the neck of the walker carrying Viggen; however, Ryden was able to score a hit with the weaponry of his tank, but drained the vehicle's power in doing so and failed to disable the walker. As the commander was forced to flee his powerless vehicle, Viggen saw the kill shot he had been waiting for and ordered his men to gun Ryden down. Before the Imperial could take revenge for the assault on his base, the rebel Gozanti-class cruiser Evac One arrived and distracted the Imperials by firing on the walker from above. This gave Rex a chance to fire from the last powered tank, and his shot crippled the walker, causing it crash into the side of the canyon. Viggen survived the crash, but was unable to prevent all of the rebels escaping once again with the supplies on board the cruiser, detonating explosives within their base as they did. He was left standing on the surface of Imvur swearing he would one day take vengeance on Ryden.
Viggen was a fair-skinned human with blue eyes, gray hair and a black moustache. After Ryden raided his base, Viggen wanted revenge and decided to personally destroy his base on the surface of Imvur, insisting on leading troops on the planet's surface as he would enjoy watching them suffer. When one of his subordinates suggested a more sensible bombardment, he threatened to demote the man for daring to question his decision. On the ground, the attack initially went more smoothly than he would have expected, with the rebels unable to damage the walkers, but he was taken by surprise when the rebel tanks managed to destroy one of the AT-ATs and left fuming on Imvur once the rebels managed to escape.
While onboard his Star Destroyer, Viggen wore a standard gray Imperial officer's uniform including the cap. Upon traveling to Imvur's surface however, he donned a set of combat armor over the top of the uniform.
Viggen first appeared in the comic strip "Vulnerable Areas," which was written by Martin Fisher and illustrated by Bob Molesworth. The strip was published in Star Wars Rebels Magazine 17 in 2016.