Hellbender (Cryptobranchus alleganiensis)

The Hellbender is the largest aquatic salamander in North America. This species has adapted to the fast-flowing rocky rivers and streams in the Eastern United States, which it navigates easily due to its unique body shape. Its flattened body can reach up to 29 inches long. 

The Hellbender hides under rocks during the day and comes out to hunt for food at night. Its diet mainly consists of crayfish, but can also eat small fish, insects, and other salamanders. 

Moreover, its blotchy brown skin provides excellent camouflage against the riverbed. It is covered in a slimy mucus that acts as a respiratory organ, allowing the salamander to absorb oxygen directly from the water.