Those Wookiees who chose to side with Chuundar, the Chieftain of Rwookrrorro Village, both before and during the Jedi Civil War and the initial conflict of the Rebellion on Kashyyyk, were known as Wookiee collaborators.
Before his rise to the position of village leader, Chuundar aided the Czerka Corporation in establishing a presence on the Wookiee homeworld of Kashyyyk. There, they initiated a trade that involved selling Wookiees into slavery. Upon discovering these actions, Zaalbar, Chuundar's younger brother, attacked him with his claws. Deemed a madclaw according to Wookiee law, Zaalbar attempted to expose Chuundar's deeds. However, their father, Freyyr, who was then the leader of Rwookrrorro, dismissed his claims due to Zaalbar's dishonor and his belief in the elder son, in accordance with tradition. Consequently, Zaalbar was exiled and soon captured by Czerka.
Approximately twenty years later, Zaalbar returned alongside Revan, who suffered from amnesia and to whom Zaalbar had sworn a life debt. By this point, Czerka Corporation had firmly established itself on Edean, as they called it, maintaining a consistent supply of Wookiee slaves through their partnership with Chuundar. Chuundar had spread falsehoods regarding his father's supposed insanity. When Freyyr learned that Zaalbar had been truthful all along, he also tried to reveal Chuundar's betrayal, but he lacked allies by that time. Stripped of his leadership role, which was assumed by his son with Czerka's support, Freyyr was forced to escape to the Shadowlands. There, the former Jedi Jolee Bindo assisted him in evading his pursuers. He remained hidden until Revan and Jolee rediscovered him. After explaining the existing circumstances, Revan persuaded the former chieftain to challenge his son once more and reclaim Kashyyyk for the Wookiees, having obtained the severed blade of Bacca's Sword from the den of a terentatek for him.
The situation reached its climax in Rwookrrorro Village's throne room, where Freyyr, Revan, Jolee, and Zaalbar confronted Chuundar, his Czerka allies, and his Wookiee collaborators. In the aftermath of the intense close-quarters combat and blaster fire, Chuundar was killed, allowing his father to regain his position as Chieftain. Those who had previously sided with Chuundar transferred their allegiance to Freyyr, marking the commencement of the Wookiee Rebellion.
In the game Star Wars: Knights of the Old Republic, Revan and their companions encounter several groups of Wookiee collaborators on Kashyyyk. It is assumed that all those who survive switch their allegiance, becoming Wookiee Rebels as they take back control of their world from the Czerka Corporation.