Pronghorn

Pronghorn are often called antelope, but they're not — they're the last living member of their own family, Antilocapridae, with no close relative on earth. What they lack in relatives they make up for in speed: pronghorn are North America's fastest land animal, capable of holding around 55 mph over real distance, second only to the cheetah worldwide. Both sexes can grow forked black horns built around a permanent bony core and sheathed in keratin that sheds and regrows every year — a trick no other horned animal pulls off. The coat is reddish-tan with bold white markings on the face, throat, and rump, and that rump patch does double duty: pronghorn flare the long white hairs upright as an alarm flag, visible to the herd from a long way off. Home is open grassland and desert-grassland across the West.