Northern Leopard Frog
The northern leopard frog is medium-sized with brown or green ground color and, on the back, large, round, black spots surrounded by light rings. It has two wide skin folds running continuously down each side of the back all the way to the groin. There usually is a large, round, dark spot on the short, blunt nose. Makes a deep, rattling snore with occasional clucking grunts, sounding like the sound of rubbing a wet thumb slowly along the surface of an inflated balloon.
Similar species: The southern leopard frog and plains leopard frog do not have such a wide and/or continuous skin fold along the sides of the back, and they lack the distinct white rings around each dark spot. The spots on the southern leopard frog's back are elongated, not round.