The pickerel frog ("Lithobates palustris", formerly "Rana palustris") is a small frog in North America. It has dark squares on its back. The squares are in lines instead of randomly scattered. Leopard frogs have circular spots. They have an orange or yellow coloration on the inside of their back legs. They are found in the east of North America. They have toxic glands in their skin that can kill other frogs.