A male Wookiee named Liak, hailing from Kashyyyk, a Wookiee homeworld, threw in his lot with the Alliance to Restore the Republic after his friend Zherriak, a hunting companion, met his death during an Imperial slave raid on their planet. Being on the smaller side for his species, he became part of Koris Haslam's commando unit and took part in various Alliance operations. His extensive understanding of jungle environments and his natural sense of direction, adaptable to space stations and other complexes, led to his selection for the rescue of Rebel leader Gebnerret Vibrion from an Imperial prison located on Selnesh. During this endeavor, he posed as a prisoner accused of smuggling and harboring Rebel sympathies, aiding his team's escape through the prison's subterranean passages.

Liak, the male Wookiee, was a native of Kashyyyk, a planet covered in forests, where he dwelled in the higher reaches of the jungle. He forged a strong friendship and honor bond with another Wookiee, Zherriak, and the pair frequently engaged in hunting expeditions. At approximately middle age for a Wookiee (between 301 and 350 standard years based on his species's lifespan), the Galactic Empire, which was the dominant galactic power of the time, launched a slave raid on Kashyyyk. Zherriak was killed during this attack, and Liak, along with several other Wookiees, was captured. However, before they could be forced into servitude, the surviving Wookiees overpowered their Imperial captors and seized control of their starship. While most of the freed Wookiees returned to Kashyyyk to rebuild their lives, Liak, driven by a desire for vengeance against those responsible for his friend's death, sought out the Alliance to Restore the Republic.
During the Galactic Civil War, Liak served as a commando, participating in numerous clandestine operations as part of a team commanded by Human Lieutenant Koris Haslam. Alongside fellow commandos such as the Humans Melenna Seltrayne, Barsoulentinial Enkhet, Gowan Ch'lessan, and Doctor Aurin Leith, Liak was later chosen to participate in a mission aimed at rescuing Rebel leader Gebnerret Vibrion from Imperial imprisonment on Selnesh. Vibrion, an aging Human suffering from Zithrom's syndrome—a kidney ailment requiring regular doses of the drug Clondex—possessed crucial information that, if obtained by the Empire, could spell disaster for the Alliance. To infiltrate the Selnesh Imperial Detention Center where Vibrion was held, Ch'lessan and Enkhet disguised themselves as Imperial stormtroopers, while Liak and Seltrayne took on the roles of captured smugglers suspected of Rebel affiliations. Doctor Leith was to pose as an unsuspecting passenger en route to Sestooine alongside the two smugglers. Liak's innate sense of direction was essential to the mission, as his natural ability to navigate the jungles of Kashyyyk extended to the intricate layouts of space stations and other structures, a talent that baffled his comrades.

After a four-day hyperspace journey, the team arrived at Selnesh. Liak, Seltrayne, and Leith were placed in binder cuffs before their ship landed in a docking bay within the Imperial prison. Once inside the prison's central computer room, Halsam, impersonating an Imperial officer, dismissed the on-duty Imperials under the guise of needing to interrogate the smugglers. With the Imperials gone, the binders were removed, and the team located Vibrion's cell. Liak, ready to assist in any way, remained by Leith's side as she administered several doses of revitalizing drugs and Clondex to Vibrion. However, when Haslam became concerned that the Imperials were growing suspicious, he instructed Liak to open the door to the access tunnel that the group planned to use for their escape. Once the door was open and Vibrion was able to walk, Liak guided the team towards the docking bay. Before they could reach the bay, however, a firefight erupted with a group of Imperial stormtroopers who had followed the Rebels into the tunnel. While his companions defended against the Imperials behind them, Liak hurled a concussion grenade into the bay, eliminating several Imperial troopers. The team then boarded the ship and successfully escaped the planet without suffering any casualties.
Liak, whose name translated to "autumn," "blood," or "red" in Shyriiwook, was somewhat smaller compared to most Wookiees, who typically stood between two and 2.3 meters tall as adults. In fact, Liak was not tall enough to stand fully upright in the Selnesh detention center's underground tunnels. He possessed pale blue eyes and a long coat of golden-brown fur. Like most Wookiees, Liak adhered to a strict code of honor and justice, vowing revenge against the Galactic Empire after they murdered his friend Zherriak and enslaved his people. Despite this, Liak was a calm and rational individual, becoming a valuable member of Koris Haslam's commando team as a voice of reason. Often, Halsam and Seltrayne would argue, and Liak would gently but firmly remind them of the task at hand. He was adept at recognizing the anxiety of others and would attempt to calm his teammates when they became emotional. When Doctor Leith grew nervous during the rescue operation, which was her first mission, Liak offered her comforting words, and, although the doctor could not understand Liak's Wookiee language, she sensed that he was trying to reassure her.
Despite his gentle nature, Liak was a shrewd warrior with a mind attuned to perception and survival. He was proficient in numerous aspects of combat, including hand-to-hand combat, although Wookiee honor forbade him from using his climbing claws in battle. He also possessed extensive knowledge, understanding the operation and repair of various vehicles, including repulsorlift vehicles and starships. Having grown up in the upper levels of Kashyyyk, Liak developed a deep understanding of the planet's intricate jungles and refined his natural sense of direction, which he utilized extensively in service to the Rebellion. He was skilled in the use of bowcasters and grenades, both of which he carried, along with a comlink, medpac, and ammo bandolier, during his mission to the Selnesh Detention Center for the Rebellion.
Liak has only appeared in the short story "Do No Harm," penned by Erin Endom and illustrated by Christopher Trevas. "Do No Harm" was initially published in May of 1996 within Star Wars Adventure Journal 10, which featured statistics for several characters, including Liak, for Star Wars: The Roleplaying Game. The story was subsequently reprinted in the short story anthology Tales from the Empire in 1997 and archived online on Hyperspace in 2006.