Appearance 
Most male Narwhals (and a few of the females, too) have a distinctive tusk growing just over their top lip. The tusk, which curls like a corkscrew, can grow to be over 6.5 feet (2 meters) long. Historians believe that the discovery of broken Narwhal tusks washed ashore helped create legends about the unicorn, a mythical land mammal with a Narwhal-like tusk in its forehead. Were it not for the tusk, the Narwhal could easily be mistaken for a Beluga Whale. Its body is a very similar shape and size, and only slightly darker in color.