Subtitles section Play video Print subtitles Narwhals are mythical creatures related to unicorns. They have a magical horn that grants wishes and they love rainbows — No, no, no, no, no, that's not right. There are lots of misconceptions and mystery surrounding narwhals. Let's start with the horn. It's not a horn. It's the narwhal's left front tooth. And it's not growing out of the forehead. It grows out of the lip. Other animals have teeth or tusks that grow outside of the mouth, like elephants and walrus, but their tusks are curved. The narwhal tooth is the only straight tusk in the world. It's also one of the few teeth that is a spiral shape. The tooth grows in a counterclockwise spiral. And it is flexible and can bend a foot in any direction without breaking. But that's not all. The tooth is actually inside out compared to other animals. All the nerves are on the outside, which is a good reason that narwhals wouldn't want to use their sensitive tooth as a sword. In fact, narwhals have never been witnessed using their tusks to fight. It is hard to know exactly what the tusk is used for, because narwhals do not survive in captivity. Current theories suggest the tusk could be used to determine social rank, impress the ladies, or communicate information about the water it has traveled through. Narwhals migrate seasonally and travel in pods through Arctic waters. Summers are often spent in the shallow, ice-free waters closer to the coast. During the winter, they stay in a smaller area and live among the shifting ice and cracks. Their underwater life is very secretive. No one has reported seeing narwhals eat or mate underwater. The mysterious narwhal has inspired myths around the world. In the Middle Ages, the narwhal tusk was sold as a unicorn horn. Physicians believed it could cure the plague, increase virility, detect poison, and even raise the dead. No wonder it was worth 10 times its weight in gold and one of the most coveted substances in Europe. It is said that thrones of Danish kings, utensils of French royalty, and Thanes' scepters were all the left front tooth of this mystical marvel.