semi-aquatic frog (family Ranidae), named for its loud call. This largest North American frog, native to the eastern United States and Canada, has been introduced into the western United States and into other countries. The name is also applied to other large frogs, such as Pyxicephalus adspersus in Africa, R. tigerina in India, and certain of the Leptodactylidae of South America.

The bullfrog's coloration ranges from green to olive or brown with a white to yellowish belly and dark-barred legs. Body length is to about 20 cm (8 inches); hindlegs to 25 cm (10 inches). Large adults weigh 0.5 kilogram (1 pound) or more. Bullfrogs usually live in or near bodies of still water. They breed in early summer; the eggs are laid in water and hatch into dark-spotted greenish-brown tadpoles. Depending on climate, the tadpole stage lasts one to three years. Many bullfrogs are caught for food.