4. Giant Chinese Salamander
Many aquatic creatures tend to be small, but not this amphibian wonder. This salamander can reach as large six feet in length, which is unheard of for an amphibian. These salamanders are on the most endangered list of animals due to a decline in habitat and due to city-wide pollutants found in most rocky-mountain streams, lakes, and typical open-water streams. Keeping these large creatures flourishing for years ahead will be a tough battle.