Kybucks are swift-footed ungulates native to the Woolwarricca prairies of Kashyyyk's inland, a brief patch of grasslands bordered by the swelling rise of the enormous jungles. The nimble mammals use the cover of tall, swaying grasses as protection from predators, and their remarkable speed and agility allows them to outrun and outmaneuver most hunters. Kybucks can run at over 90 kilometers per hour, and often pepper their sprints with sudden twisting jumps that can reverse their direction entirely. Male kybucks have short horns atop their head. Different kybuck breeds can be easily identified by variations in horn shape and size.
Kybucks mate for life, raising an annual litter of two or three foals in rearing grounds protected by barbed thicket. If alone, kybucks tend to flee from any threats, but if an intruder threatens a kybuck's young, the mother and father will fiercely defend their territory, using leaping kick attacks and horned head-butts to dissuade any predator.
The plains Wookiees of the Woolwarricca laud the kybuck for having protective familial instincts that mirror the traditional Wookiee honor family. Wookiees do not hunt kybucks, and some chieftains have domesticated kybucks as symbols of status.
For his role in healing an ailing Woolwarricca princess, Yoda was given a neutered kybuck as a gift from a grateful Wookiee elder. Yoda took the kybuck with him to Coruscant, keeping him in an expansive menagerie deep within the Jedi Temple. Having no need for possessions, Yoda never claimed ownership of the kybuck. He nonetheless developed a bond with the creature, and found the small animal able to support his weight as a mounted steed.
The kybuck has no spoken name. Instead, Yoda called to it through the Force. Yoda took care never to exert too much influence on the animal's mind. He was pleased to find that the kybuck developed a protective bond with him, and would charge into dangerous situations alongside Yoda. To Yoda's mind, he was not the kybuck's master, but rather its friend.
During the Clone Wars, Yoda rode the kybuck into battle on occasion, particularly in the defense of Coruscant during General Grievous' audacious attack on the capital. Though the kybuck showed remarkable courage in facing laser fire, explosions and battle droids, Yoda did not take the beast into the thickest of the fighting.
It is not known what happened to the kybuck after the fire at the Jedi Temple the night of Order 66.