The Narwhal is characterized in the male by a long spirally twisted ivory tusk or tooth, which can grow up to 3metres in length and projects from the left side of its head. Females sometimes grow a small tusk of their own, but it does not become as prominent as the male's.

The male body's coloration is mottled grey-green, cream and black, and whitens on the belly with age. The female Narwhal tends to be smaller than males. The young tend to be gray, blue-gray or black in coloration.

Narwhals have a stout body with a small, rounded head, bulbous forehead and a very slight beak. They have short flippers, somewhat like a dolphin or porpoise, which are broad with upturned tips. They have no dorsal fin, only a ridged back. Narwhal tails tend to be fan-shaped and they have a fluke with deep notches in the center.

The Narwhal grows up to 6metres in length and a male can weigh up to 1600kgms. Narwhal calves are six feet long and weigh 176 pounds when they are born after a gestation period of approximately 14 months.

The ivory tusk tooth, which characterizes the Narwhal, grows right through the narwhal's upper lip. Scientists are not certain of the tusk's purpose, but some believe it is prominent in mating rituals, perhaps used to impress females or to battle rival suitors.

They most commonly travel in groups 15 to 20 and feed on fish, shrimp, squid, and other aquatic fare. Narwhals commonly dive to 1600 feet though they can dive in excess of 3300 feet for over a 20 minute period. During the winter months, the narwhal live offshore near very heavy pack ice and move through leads and narrow channels during the spring ice melt.

The Inuit people hunt the narwhal, amongst the pack ice, for their long tusks and their skin, an important source of vitamin C in the traditional Arctic diet.