Scientific Name: Lutra lutra Life Span: 10-20 years Diet: Fish, shellfish, mammals, frogs, water birds, and insects Size: 2-4 feet A top predator in the local food chain, they inhabit streams, rivers, and reservoirs across Korea. Near USAG Humphreys, otters mostly live in Anseong River. Listed as endangered and a natural monument in South Korea. (Courtesy photo)