<human>:  I have a question about the book The Dirwhal. Why is the narwhal called a narwhal?
<bot>: The narwhal is a species of toothed whale. It is named after the narwhal, a mythical creature with a long spiraled horn. The narwhal is a very rare and mysterious animal. It is the only member of the family Monodontidae, which is a very small family of toothed whales.