Tyvak, a Shistavanen male, held the position of second-in-command under the crime lord Jaum. Jaum's criminal operations were based on the planet Andelm IV during the Galactic Civil War. During this period, Chewbacca launched an assault on Jaum's mine. Although Tyvak initially gained the upper hand, Chewbacca later set him on fire.
As a male of the Shistavanen species, Tyvak acted as the primary lieutenant for Jaum, a crime lord. Jaum's operations were centered on the planet Andelm IV, located in the Outer Rim Territories of the galaxy, during the Galactic Civil War.
Leading up to the Battle of Yavin, Jaum had enslaved individuals through deception and debt, forcing them to extract Andelm beetles from his mine. These beetles were crucial for manufacturing blasters. Tyvak accompanied his boss to the residence of Arrax and his daughter, Zarro, who were also indebted to Jaum, leading to their enslavement in the mine. A few days afterward, Zarro managed to escape from the caverns. Jaum tasked Tyvak with hunting her down and bringing her back. Tyvak, along with several guards, ventured into a city on Andelm IV and began their search in a cantina. A towering Wookiee drew Tyvak's attention, leading to a confrontation. Chewbacca, the Wookiee, simply stared at Tyvak, who eventually moved on, feeling somewhat defeated. Unbeknownst to Tyvak and the guards, Chewbacca was concealing Zarro beneath his table.
Later that night, Jaum, Tyvak, and a guard met with an Imperial officer, stormtroopers, and a scientist from the Galactic Empire in a remote area of Andelm IV, far from the spaceport. They were there to negotiate the terms of Jaum's syndicate providing the Empire with dedlanite from the Andelm beetles. This was intended to support the Empire's war efforts following the destruction of their Death Star battle station by the Rebel Alliance during the Battle of Yavin.
The following day, Zarro was recaptured by Tyvak's guards. However, unknown to them, this was part of a larger plan to free everyone from the mine with Chewbacca's help, whom Zarro had convinced to assist her. Jaum and Tyvak confronted the workers, including Arrax, informing them of their impending sale to the Empire as permanent slaves. The workers were horrified, and one man attempted to attack Jaum but was swiftly killed. Tyvak then organized the guards to suppress the uprising. However, Chewbacca had entered the mine and defeated many guards before Tyvak and Jaum set a trap. Tyvak positioned crates of beetle larva at the mine's exit and fired on them with a sniper rifle as Chewbacca emerged, causing the larva to explode and trapping and killing many workers.
Tyvak commented to Jaum that Shistavanens had a saying: kill Wookiees whenever possible, as they bring bad luck. Tyvak and Jaum then returned to their V-35 Courier landspeeder, lamenting the loss of their workforce. Jaum remained optimistic about compensation from the Empire, while Tyvak believed the Empire would simply seize their assets. He then informed Jaum that he believed Chewbacca had survived and would seek vengeance. Shortly after, in a nightclub, Jaum killed a former guard who revealed he had been freed by a Wookiee. Tyvak reminded Jaum that he knew Chewbacca was alive and, on Jaum's orders, gathered the guards while Jaum requested reinforcements from Imperial Commander Kai.
As instructed, Tyvak assembled the remaining guards in the hangar to prepare for an assault on Chewbacca and his allies. Soon after, a group of Imperial stormtroopers, scout troopers, and an All Terrain Scout Transport arrived in a Sentinel-class landing craft, reinforcing their numbers. However, while they were preparing, Chewbacca and Zarro arrived at the hangar disguised as security for the delanite and beetle larva shipments. Jaum discovered their deception, forcing Chewbacca to reveal himself and attack. Tyvak rushed into battle, challenging Chewbacca to a duel with his vibro-blade, determined not to "let the Wookiee win," as the saying went. Chewbacca roared at the Shistavanen and activated a nearby engine, which unleashed a blast of fire onto Tyvak. Tyvak fled, engulfed in flames.
Tyvak was a cruel enforcer, serving as the right-hand man and bodyguard of the Andelm IV gangster Jaum. He led hunts for escaped slaves like Zarro, who defied Jaum's exploitation. Tyvak harbored a strong animosity towards Wookiees and was prepared to dedicate significant resources to eliminating Chewbacca. While Tyvak supported Jaum's plan to profit from a dedlanite mine on Andelm IV, he feared the Galactic Empire could easily take over their operation. Jaum considered Tyvak a pessimist and believed he underestimated the tenacity of Wookiees.
Tyvak was also a skilled melee combatant, capable of fighting Chewbacca with a vibro-blade. However, the Wookiee outsmarted him by setting him on fire with an engine. As a result, Tyvak was burned and unable to continue fighting. Jaum was angered by the apparent demise of his friend and vowed to send bounty hunters after Chewbacca.
Tyvak's first appearance was as a minor antagonist in Gerry Duggan's 2015 Marvel comic series Star Wars: Chewbacca, which focused on the Wookiee as the main character. Phil Noto provided the artwork for the character.