Narwhales (also called Narwhals and Unicorn Whales) are a species of toothed whale found in the arctic regions. In the Wolves of the Beyond series, they inhabit the Frozen Sea.
Narwhals are medium-sized whales, (13 to 18 ft, excluding tusk) and are around the same size as beluga whales, whom they share the Monodontidae family with. Males (and on rare occasions, females) grow long, spiraling tusks, which are actually their left canine tooth. These tusks can grow up to 10ft, and are hollow. There are millions of nerve endings in the tusk, used to sense the water and possibly used to get a feeling for the water currents.
The whales themselves have white undersides, and are dappled with brown and black markings. At birth they are almost completely dark, having more white patches as they mature. Some old whales may almost be completely white. This appearance also gave it its name, as it's mottled coloring made it appear like a drowned, rotting corpse, with Norwegian for "corpse" being nár