The hellbender is one of the largest salamanders in North America. It's also one of the most unmistakable, with its flattened head, body, and tail, and loose, wrinkled flaps of skin along its sides. Hellbenders are found in clear, fast-flowing rivers and streams. By day, they hide under rocks and debris. At night, they come out to look for food.

Scientific name: Cryptobranchus alleganiensis
Habitat: clean rivers and streams from southwest New York to northern Alabama and Georgia
Size: 12 to 27 inches long
Diet: crayfish, insects, worms, and small fish
Characteristics: flattened body and wrinkled skin; short powerful legs; gray or brown
Significance: the largest salamanders of the western hemisphere

Image credits: main image: courtesy of Brad Moon, California Academy of Sciences.