The Newfoundland dog is a large working dog. They can be either black, brown, or white-and-black. They were originally bred and used as working dogs for fishermen in Newfoundland. These dogs have huge lung capacity for swimming extremely long distances and a thick, oily, and waterproof double coat which protects them from the chill of icy waters. The double coat makes the dog hard to groom, and also causes a lot of shedding to occur. The droopy lips and jowls make the dog drool, especially in high heat. Newfoundlands are ideal companions in the world of therapy and are often referred to as the nanny dog. The breed was memorialized in 'Nana', the beloved guardian dog in J. M. Barrie's Peter Pan.