A zoo denizen is an animal that lives in a zoo. The most common zoo denizens are ANIMALS, BEASTS, seals, and otters. ANIMALS are typically mammals, birds, reptiles, amphibians, and fish. BEASTS are large, wild ANIMALS such as lions, tigers, and bears. Seals are aquatic mammals that live in the ocean and have flippers instead of feet. Otters are semi-aquatic mammals that live both on land and in the water. All of these ANIMALS can be found in zoos around the world.