Garnac was a male Trandoshan who made his living as a big game hunter. He operated a hunting guild consisting of other Trandoshans, one of whom was his own son, Dar. Garnac's guild specialized in conducting hunts on the moon of Wasskah, where they would abduct sentient beings and transport them to one of Wasskah's islands. Once there, the captives would be released, only to be hunted down without mercy by the Trandoshans.
During the Clone Wars period, specifically in 20 BBY, Lo-Taren, a member of Garnac's guild, managed to capture Ahsoka Tano, a Jedi Padawan. She was then taken to Wasskah, the Trandoshan moon. Garnac and his guild proceeded to hunt Tano along with other prisoners, including three younglings named Kalifa, Jinx, and O-Mer. Garnac's son, Dar, had not yet slain a Jedi, but he was presented with an opportunity during an initiation hunting trip with the other Trandoshan hunters. However, events unfolded differently than anticipated. Kalifa used the Force push ability to knock Dar off the vines, resulting in his fatal fall. By this time, Garnac had successfully located Tano and Kalifa in the dense foliage. Witnessing his son's death, Garnac, in a fit of rage, used a sniper rifle to shoot and kill Kalifa. He then angrily shouted at Tano, vowing to exact revenge on the "Jedi whelps" for his son's demise, promising that neither she nor her comrades would escape their hunt.
Later on, Ahsoka and her companions joined forces with Chewbacca, a Wookiee who had been aboard the Trandoshan dropship, specifically a HCT-2001 Dragonboat-class Reugeot 905. They were being hunted after the Trandoshan prisoner transport crashed, resulting in the deaths of the Trandoshan pilots Clutch and Goron due to the actions of Tano and the Jedi younglings. This event led to a failed attempt to escape the hunting island of Wasskah. The following morning, Garnac and his forces investigated the wreckage and concluded that the younglings were organized, audacious, and had Chewbacca as an ally.
After kidnapping the Trandoshan named Smug and using a mind trick to convince him to get his friend Krix to assist them, the three young Jedi and their Wookiee companion managed to commandeer a Trandoshan hunting speeder. They then flew up and attacked the Trandoshans' base, which was an Ubrikkian floating fortress. Garnac and two of his subordinates emerged from the trophy room. Garnac commanded his troops to kill the younglings and retrieve their skins. In response to O-Mer firing the hijacked hover pod's rotary blaster at two of Garnac's troops, Garnac retaliated by firing a rotary repeating blaster cannon mounted on the upper deck at O-Mer as the youngling piloted the pod around the lower deck's perimeter, causing the pod to crash into the lower deck. He commended the younglings' valiant effort, singling out Tano, whom he identified as "Togruta," and declared that she would be a prized addition to his trophy collection.
However, Wookiee reinforcements, led by General Tarfful, arrived shortly thereafter on the Halo, the ship of Sugi, a Zabrak bounty hunter. They had received a distress beacon via a transmitter that Chewbacca had constructed. As the battle intensified and the Wookiees gained the advantage, Garnac retreated into the trophy room, pursued by Tano. A fierce struggle ensued between the two amidst the chaos, during which Garnac employed brute strength, hand-to-hand combat, an axe, a knife, and a Trandoshan blaster in an attempt to kill Tano. Ultimately, she prevailed and declared Garnac defeated. Garnac reiterated that Tano would pay for his son's death. Tano countered that Dar's death was a result of his own actions, not hers. Garnac then turned and reached for the blaster, prompting Tano to warn him against it. Ignoring her warning, he reached for the weapon, leading Tano to use the Force to push him out of the trophy room, sending him flying through the doors, over the railing, and down to the lower deck. Despite the significant fall, Garnac survived.
Sometime between 19 BBY and 18 BBY, after the reformation of the Galactic Republic into the Galactic Empire, Garnac was present on the planet Serolonis. While there, he associated with Grini Millegi, a Dowutin gangster who was sponsoring Jet Venim, a Nosaurian riot racer, in the Safa Toma Classic.
Garnac was a Trandoshan male standing at a height of 2.1 meters, equivalent to 6 feet and 11 inches. His physical features included orange eyes and gray skin adorned with green and yellow markings. He possessed a ferocious, evil, thuggish, ruthless, and bloodthirsty nature. He led a Trandoshan hunting group that specialized in capturing and hunting individuals for sport on Wasskah, the moon of Trandosha. Garnac reveled in violence and enjoyed facing formidable opponents in combat. He was also known for his macabre fascination with collecting trophies and antiques, such as mounted animal heads and creatures. The thrill of stalking prey through Wasskah's underbrush was something he particularly savored. However, Garnac's deepest affection was reserved for his son, Dar, whom he cherished greatly. He proudly observed Dar's involvement in the hunt, particularly his pursuit of the Padawan Kalifa. However, Garnac underestimated the resilience of their Padawan target, who used the Force to push Dar to his death. Dar's demise plunged Garnac into a state of enraged frenzy, fueling an obsession with avenging his son's death by killing the Jedi younglings, starting with Kalifa, whom he shot with his sniper rifle. Ultimately, his thirst for revenge proved to be his downfall, as it clouded his judgment and led to his defeat at the hands of Ahsoka Tano.
As the leader of his hunting party, Garnac possessed extensive experience as a hunter and was a skilled fighter, utilizing a variety of weapons, including a knife, a Trandoshan axe, a sniper rifle, a Trandoshan blaster, and a blaster pistol. His hunting prowess was evident in the numerous trophies displayed on the walls of his guild, which included Wampas, Wookiees, and Rancors, along with other dangerous creatures. Garnac was also proficient in hand-to-hand combat, as demonstrated during his intense fight with Ahsoka Tano. Furthermore, he was an experienced tracker and sharpshooter with notable survival skills.
Garnac's first appearance was in "Padawan Lost," the twenty-first episode of Star Wars: The Clone Wars season 3, where he was voiced by Zach Hanks.
A Trandoshan character bearing a resemblance to Garnac appeared in "Faster," the fourth episode of Star Wars: The Bad Batch's second season, which aired on January 18, 2023. Although not explicitly identified as Garnac in the episode, an official promotional asset released by Walt Disney Studios through Getty Images on the same day confirmed the Trandoshan's identity as Garnac in the asset's caption. However, this contradicts the information presented in Star Wars: The Clone Wars: Character Encyclopedia - Join the Battle!, which states that Garnac was killed by Ahsoka Tano in the Star Wars: The Clone Wars episode "Wookiee Hunt."