The American Bullfrog is the largest of all North American frogs. They can grow to a length of over 8 inches and can weigh as much as 1.5 pounds. They are usually green or brown with brown spots and circular ear drums ,called tympanum, on either side of their heads. They will ambush and eat almost anything they can fit into their mouths, such as insects, mice, fish, birds, and snakes. Males are highly territorial. The male's call resembles the mooing of a cow. The average lifespan of an American Bullfrog in the wild can be from 7 to 9 years.