The Ranidae or true frogs can be found in most countries except Antarctica. The true frogs can be found in North America, northern South America, Europe, Asia, Madagascar, Africa, East Indies, New Guinea, and Australia. The bullfrog is the largest true frog in North America. Usually, true frogs are smooth, moist-skinned frogs, with large, powerful legs and have webbed feet. The smallest true frogs are the Wood frog ("Rana sylvatica"). The largest is the Goliath frog ("Conraua goliath"). True frogs are semi-aquatic frogs. They live near water.