There may be no such thing as a unicorn, but a narwhal comes close. Narwhals are arctic whales that have a long, spiral tusk sticking out the left corner of their mouths. That tusk is actually a reeeeeeally long tooth that can grow 10 feet long! Unicorn drawings from hundreds of years ago had twisty horns like that, so maybe narwhals gave them the idea for this magical animal. But narwhals aren't so easy to find, either!