The Narwhal is a type of whale that gets its name, meaning “corpse whale”, from its bluish, blotchy skin. The most interesting thing about this whale, however, is the long tooth that juts out of its head. Narwhals have two upper teeth, and the male’s left tooth grows up to 10 feet in length. No one is aware of the exact use for the tooth. Some say it is used during mating season to fight off other males, while others think it may be a sensory organ, used to detect its surroundings. Whatever it’s used for, it must make eating difficult!