Katkins are a mutated form of the common domestic house cat, standing about one meter (3 feet) tall when walking erect (which they often do). Coloration can range from white to orange-striped, but gray-striped and brown or black solid colors are the most common. These intelligent creatures have not lost their fangs or their claws, although the claws of their manipulative forepaws are not proportionately as long as the rear ones. Katkins are rather shy and reclusive, using their heightened speed and balance to live arboreal lives, ranging amidst the upper branches of woodlands to hunt and explore. One or more Katkins will construct a well concealed hut of woven vines and branches high up in the largest of trees, dwelling there during summer months. Winter quarters are typically in hollow tree trunks. Katkins have both sound and thought imitation capabilities; so, in addition to their normal body weaponry (two claw attacks and a bite), they have dangerous imitative abilities as well. Katkins have been known to possess and use small technological devices (pistols, vibro daggers, etc.). Employment of normal weapons suited to their size and strength is fairly common around the creatures' home.
(The creature first appeared in first edition Gamma World module: GW1 Legion of Gold)