The cougar (Puma concolor), also known as puma, mountain lion, mountain cat, catamount or panther, depending on the region, is a mammal of the family Felidae, native to the Americas. This large, solitary cat has the greatest range of any large wild terrestrial mammal in the Western Hemisphere, extending from Yukon in Canada to the southern Andes of South America. An adaptable, generalist species, the cougar is found in every major American habitat type. It is the second heaviest cat in the Western Hemisphere, after the jaguar. Although large, the cougar is most closely related to smaller felines and is closer genetically to the domestic cat than to true lions. Like the smaller felines, the cougar is nocturnal.

A capable stalk-and-ambush predator, the cougar pursues a wide variety of prey. Primary food sources include ungulates such as deer, elk, moose, and bighorn sheep, as well as domestic cattle, horses and sheep, particularly in the northern part of its range. It will also hunt species as small as insects and rodents. This cat prefers habitats with dense underbrush and rocky areas for stalking, but it can also live in open areas. The cougar is territorial and persists at low population densities. Individual territory sizes depend on terrain, vegetation, and abundance of prey. While it is a large predator, it is not always the dominant species in its range, as when it competes for prey with other predators such as the jaguar, grey wolf, American Black Bear, and the grizzly bear. It is a reclusive cat and usually avoids people. Attacks on humans remain fairly rare, despite a recent increase in frequency.