Narwhal
unicorn of the sea 

Often dubbed the unicorns of the sea, narwhals are strange and beautiful creatures with long tusks protruding from their heads. Members of the population of more than 80,000 can weigh up to 4,200 pounds and grow as long as 17 feet in length. Read on to learn more about these fascinating animals.
What is a narwhal tusk?
The narwhal tusk—most commonly found on males—is actually an enlarged tooth with sensory capability and up to 10 million nerve endings inside. Some narwhals have up to two tusks, while others have none. The spiraled tusk juts from the head and can grow as long as 10 feet.
Where do narwhals live?
Unlike some whale species that migrate, narwhals spend their lives in the Arctic waters of Canada, Greenland, Norway, and Russia. Most narwhals winter for up to five months under sea ice in the Baffin Bay-Davis Strait area.