A large hare of North America, the white-tailed jackrabbit (Lepus townsendii) is most easily recognized by its long, antennae-like ears, which are grey on the outside, white and brown on the inside, and have conspicuous black tips. This species is the only jackrabbit that has two annual moults. During the summer, the thin, coarse coat is dark brown to greyish-brown on the upperparts and white or pale grey on the underparts. In northern parts of its range, where snowfall is regular, the white-tailed jackrabbit becomes all white during winter with some grey around the eyes and throat. However, in southern parts of its range, it only develops white sides. The tail, which gives this hare its common name, it white all year round, with a dusky stripe on the upper side.

Built for speed, with a slender, lean body and well developed, long hind limbs, the white-tailed jackrabbit is capable of bursts of speed of up to 40 miles per hour. This athletic mammal is even able to jump higher than 3.6 metres.