During the Second Imperial Civil War, Anson Trask served the Galactic Empire as a male Human stormtrooper. Following the path of his father, Trask became a member of the 407th Stormtrooper Division, specifically assigned to Joker Squad. Shortly after his training concluded, he participated in the Battle of Borosk against forces who remained loyal to Roan Fel, the former Galactic Emperor. After the battle concluded, Darth Maleval executed Lieutenant Gil Cassel, the commanding officer of Joker Squad; in response, Trask took the life of the Sith Lord to safeguard his fellow soldiers.
Following the events that transpired on Borosk, only Trask and Sergeant Ran Harkas were left in Joker Squad. However, the unit was soon reformed, and Trask received a promotion to the rank of corporal. Subsequently, Joker Squad was dispatched to Ossus with the mission of locating a group of Jedi who were concealed on the planet. While Trask's team was searching the lower levels of the Ossus Jedi Academy, the Jedi Shado Vao employed a mind trick to persuade Trask to cease the search and return to his Star Destroyer. Later, Joker Squad was reassigned to the First Sith Imperial Strikeforce with the task of eliminating any survivors from Darth Azard's orbital bombardment of Napdu, the moon of Da Soocha. This bombardment was an act of revenge for harboring refugees escaping the recent genocide of the Mon Calamari. In 138 ABY, Joker Squad participated in an attack targeting the Jedi Hidden Temple located on the planet Taivas. When Harkas was killed in action, Trask stepped up to lead the remaining members of the unit and continued the assault.

Anson Trask, a male Human, was the offspring of a stormtrooper within the Fel Empire's 407th Stormtrooper Division. Throughout his childhood, Trask listened to his father discuss "the honor of the armor," which inspired him to enlist as a stormtrooper himself. By the time Trask had finished his training in 137 ABY, the Empire had fractured into a civil war between those loyal to Darth Krayt, the Dark Lord of the Sith, and those loyal to Roan Fel, the deposed Galactic Emperor. Consequently, Trask found himself serving in Krayt's Empire. Adhering to the Empire's principle of "continuity of service," Trask, as the son of a stormtrooper, was presented with the option of joining the same division in which his father had served. He was subsequently assigned to Joker Squad, specifically in Company C, 9th Battalion, of the 407th Stormtrooper Division.
A mere ten days after completing his training, Trask arrived on Yinchorr to assume his position within Joker Squad. Before being dropped off, he received directions to his new squad; however, as the 407th prepared to depart on a mission, his directions didn't align with the camp's layout. Finding minimal assistance from his fellow stormtroopers, he decided to ask for directions, unfortunately approaching the Sith Lord Darth Maleval. Maleval was annoyed by Trask's perceived lack of discipline, but Sergeant Ran Harkas of Joker Squad intervened, saving Trask from the wrath of the Quarren Sith Lord by informing Maleval that Trask was a "noob," fresh out of training.
Harkas then introduced Trask to the rest of the squad, though his reception was somewhat subdued. The seasoned soldiers of Joker Squad had witnessed many new recruits arrive and were accustomed to their short lifespans. They even had a betting pool on how long Trask would survive, believing that his own estimate of a month was overly optimistic.

Shortly after Trask's arrival, Lieutenant Gil Cassel, the squad's commander, briefed the group on the upcoming mission. The 908th Stormtrooper Division had become stranded on Borosk after a failed attempt to defect to Roan Fel's Empire-in-exile. The Moff Council had decided to deploy the 407th, under the command of Darth Maleval, to confront the 908th in an effort to defeat the defectors while preserving the base.
Joker Squad was among the first units to arrive at Borosk, and their initial orders involved capturing and securing gun and shield emplacements along the perimeter wall of the 908th's fortress. Initially, Trask was overwhelmed by the chaos and noise of battle, struggling to differentiate enemy stormtroopers from their own, which caused him to freeze. However, as the day progressed, the realization that he must kill or be killed overcame his hesitation, and he joined the battle, achieving his first kill. After Joker Squad successfully secured the gun platform and the 908th retreated further into their headquarters, the squad was allowed to stand down for the night. However, they were soon confronted by Maleval, who had discovered that Cassel had proposed a truce to allow the 908th to surrender. Maleval declared that there would be no surrender and that the 908th's destruction would serve as a warning to other deserters. Furthermore, knowing that Cassel's brother, Jared, served with the 908th, Maleval questioned Cassel's loyalty and insisted that Joker Squad lead the charge the next day, threatening to kill the entire squad if any of them faltered.

Joker Squad breached the main fortress at midday on the second day of the battle and proceeded to move through the corridors, engaging in close-quarters combat with troopers of the 908th. The battle soon took its toll on Joker Squad. Vax Potorr was killed by a mine as Joker Squad cleared the main mess hall, while a stray blaster shot caused Jes Gistang's power pack to explode, resulting in her death and injuries to Harkas. Despite their losses, Joker Squad continued to fight until the 908th was defeated. After the battle, Maleval brought the captured Jared to his brother and ordered Cassel to kill him. When Cassel refused, both brothers were executed by the Sith Lord. Joker Hondo Karr, enraged by the death of his commander, attacked Maleval, only to be ensnared in the Sith Lord's shock whip and nearly killed. Acting instinctively, Trask shot Maleval in the back, killing the Sith Lord and saving his comrade. The official report listed both Maleval and Karr, who disappeared after the battle, as killed in action. Trask and Harkas were the only members of the squad to officially survive.
Trask earned Harkas's respect during the battle and was no longer considered a "noob." As the wounded Sergeant was taken for treatment, he instructed Trask to take charge of the replacement troopers. Trask soon assumed the role of mentor when a new recruit arrived on Borosk seeking Joker Squad. Referring to the man as a "newbie," Trask took the recruit under his wing as the process of rebuilding the squad began. He continued to serve under Harkas in the following months, as Joker Squad was rebuilt into a specialized unit capable of handling a variety of missions, eventually earning a promotion to the rank of corporal.
Following the events on Borosk, the Empire grew suspicious that Ossus, abandoned by the Jedi since a Sith attack on the Jedi Academy there seven years earlier, was being used as a hiding place by surviving Jedi. The Sith Lord Darth Stryfe led an Imperial force to investigate, and Trask and Harkas were among the stormtroopers sent to the planet's surface to conduct a search, though they initially failed to locate any Jedi. Eventually, the squad split up, and while Harkas continued to search the surface, Trask led another stormtrooper to investigate the lower levels of the Jedi Academy, where they encountered a small group of Jedi and Yuuzhan Vong. Although the Yuuzhan Vong warrior Choka Skell advocated for killing the intruders, Jedi Master K'Kruhk knew that this would only confirm their presence and attract more Imperials to the planet, along with their Sith masters. Instead, the Jedi Shado Vao used a mind trick to convince Trask that the academy was deserted and that it was time to leave. Trask dutifully obeyed and returned to a waiting Star Destroyer. Stryfe, however, remained unconvinced by the apparent absence of Jedi and ordered the destruction of the academy.

Later that year, Trask and Joker Squad were among the stormtrooper squads assigned to the First Sith Imperial Strikeforce, under the command of Moff Rulf Yage. After Sith Regent Darth Wyyrlok ordered the extermination of the Mon Calamari, as well as all life on their homeworld of Dac, in retaliation for the species' support of the Galactic Alliance, the Quarren Sith Lord Darth Azard led Yage's forces to the planet Da Soocha in search of Mon Calamari refugees. When the Hutt Azzim Anjiliac Atirue denied all knowledge of refugees, Azard ordered the poisoning of Da Soocha's oceans and the bombardment of its moon Napdu. After the turbolasers ceased firing, Trask joined Joker Squad on the surface of the moon under orders to shoot every body they found to ensure that there were no survivors.
The war eventually reached its climax after Roan Fel's Imperials formed an alliance with Galactic Alliance Remnant forces under Admiral Gar Stazi and the surviving Jedi. In 138 ABY, after learning of the Jedi's Hidden Temple on Taivas, Darth Krayt ordered an attack, hoping to draw the alliance members into a final confrontation. Joker Squad was among the units assembled for the battle. The attack began with an orbital bombardment, but when this proved ineffective due to the planet's high cliffs and strong magnetic field, Krayt ordered Imperial Moff Geist to lead ground forces against the temple. After receiving the order to attack, Joker Squad moved in, with Trask leading Besh Team. In the midst of the battle, Harkas was killed, and Trask ordered Joker Squad to rally on him. Ultimately, Krayt's troops won the battle, although most of the alliance forces managed to escape.
Anson Trask grew up hearing about the honor of stormtrooper service from his father, a 407th veteran, and desired to become a stormtrooper himself. However, his initial experiences in the 407th, beginning with the unwelcoming reception from Joker Squad, disillusioned him. He soon discovered that the realities of war were something that simulations had failed to prepare him for, causing him to initially freeze in battle. Fighting against other stormtroopers made him question what his father would think of what had become of the Stormtrooper Corps. At Borosk, Trask observed Darth Maleval in combat and was shocked by the number of ways the Sith Lord found to kill his enemies and the apparent joy he derived from it. When Maleval threatened Hondo Karr's life, Trask instinctively shot the Sith Lord to save his fellow trooper. Despite his reservations, Trask continued to perform his duty and follow orders, quickly evolving into a hardened soldier. However, he continued to question the Empire's methods, later expressing his concerns about Joker Squad's mission to kill any survivors of the bombardment of Napdu to Harkas. His superior reminded him to keep his concerns to himself and to carry out his orders.
John Ostrander created Anson Trask for Legacy (2006) 4, the fourth issue of the Star Wars: Legacy comic series, which was first published on October 11, 2006. Although his initial appearance was largely separate from the series' broader storyline, he reappeared within the main story in the Claws of the Dragon story arc and later in Legacy (2006) 48. Following the conclusion of Star Wars: Legacy, Trask appeared in the third and fourth issues of its successor series, Star Wars: Legacy—War. The character was also featured in an entry in 2008's The Complete Star Wars Encyclopedia.
An Entertainment Earth exclusive action figure of Anson Trask was revealed at Comic Con International 2008 as part of Hasbro's Star Wars: The Legacy Collection Joker Squad six-pack.