A pet, or companion animal, is an animal kept primarily for a person’s company or entertainment rather than as a working animal, livestock or a laboratory animal. Popular pets are often considered to have attractive appearances, intelligence and relatable personalities, but some pets may be taken in on an altruistic basis (such as a stray animal) and accepted by the owner regardless of these characteristics.

Two of the most popular pets are dogs and cats; the technical term for a cat lover is an ailurophile and a dog lover a cynophile. Other animals commonly kept include: rabbits; ferrets; pigs; rodents, such as gerbils, hamsters, chinchillas, rats, mice, and guinea pigs; avian pets, such as parrots, passerines and fowls; reptile pets, such as turtles, alligators, crocodiles, lizards, and snakes; aquatic pets, such as fish, freshwater and saltwater snails, amphibians like frogs and salamanders; and arthropod pets, such as tarantulas and hermit crabs. Small pets may be grouped together as pocket pets, while the equine and bovine group include the largest companion animals.