The cougar, also known as the panther, mountain lion, catamount, or puma, is a large cat native to the Americas, second in size only to the stockier jaguar. It is largely solitary by nature and considered both nocturnal and crepuscular, although daytime sightings do occur. It is an ambush predator that pursues a wide variety of prey. Primary food sources are ungulates, particularly deer, but it also hunts smaller prey, such as rodents. The head of the cougar is round, and the ears are erect. Its powerful forequarters, neck, and jaw serve to grasp and hold large prey. It has four retractile claws on its hind paws and five on its forepaws, of which one is a dewclaw. The larger front feet and claws are adaptations for clutching prey. Cougars are slender and agile members of the Felidae. They are the fourth largest cat species worldwide; adults stand about 24 to 35 inches tall at the shoulders. Adult males are around 7 ft 10 in long from nose to tail tip, and females average 6 ft 9 in.

Cougars were extirpated from the eastern and central parts of North America within 200 years following European colonization, except for the remnant subpopulation in south Florida. Cougars live in a wide variety of environments including montane coniferous forests, grassland, swamps, lowland tropical forests, dry brush country, and any other areas that offer adequate cover and prey. They use dense vegetation, rocky crevices, and caves for shelter. Cougars are territorial and live at low population densities. Individual home ranges depend on terrain, vegetation and abundance of prey. It is reclusive and mostly avoids people. Fatal attacks on humans are rare but increased in North America as more people entered cougar habitat and built farms. The cougar prefers large mammals such as mule deer, white-tailed deer, elk, moose, mountain goat and bighorn sheep. It opportunistically takes smaller prey such as rodents, lagomorphs, smaller carnivores, birds and even domestic animals including pets.