The Narwhal is unlike any other cetacean. The male has a long spiralling tusk which is not normally possessed by the female. During the 17th century the Narwhal tusk was thought to have been the horn of the legendary unicorn.
Studies suggest that males engage in aggressive behavior when competing for females.
Scars attributed to tusk action have been found on the heads of adult males which are more likely to have broken tusks. They are similar in shape and size, they have short beaks, rounded heads, lack dorsal fins and have a thick layer of blubber. The head of the Narwhal is proportionately small with a bulbous forehead. All have a very slight beak, short flippers and flukes which appear to be on 'backwards'. The Narwhal lives mainly in the High Arctic, often amongst the pack ice and generally offshore.