The Myyydril constituted a group of Wookiees, along with other sentient beings, who inhabited the planet Kashyyyk in the period leading up to the Clone Wars.
Prior to the Clone Wars, a band of Trandoshan slavers gained access to Kerritamba Village, which served as the settlement for the Myyydril. Hosdra, a Myyydril tribe member, tried to assassinate the village's chief. Consequently, the Myyydril were compelled to abandon their settlement. For several days, they roamed the forests until they stumbled upon caverns located within Mysess Glade. They established a new settlement inside these caverns and started to reconstruct their clan. Nonetheless, by 25 BBY, the tribe's population was decreasing due to an unexplained cause.
Later investigations revealed that Urnsor'is, non-sentient parasites, were preying on the Wookiees. Facing a dire struggle for survival, the Myyydril Wookiees engaged in a fierce conflict against the Urnsor'is; however, they were unable to overcome them. The Poltur Virus quickly propagated throughout the tribe, resulting in a further reduction in their numbers. A Twi'lek female, Yraka Nes, dedicated several weeks to searching for a remedy for the virus, thereby aiding the Myyydril in their survival.
Notable individuals belonging to this clan included Kallaarac, who was the clan's chief; Hosdra; Attiera; and Froera, her daughter.