Dragons are mythical creatures that have been part of stories, books, and movies for thousands of years. They usually look like big reptiles with wings, scales, and sometimes horns and tails. They are often said to be able to breathe fire, and are thought to be very powerful and magical. People sometimes picture dragons fighting against brave knights, protecting hidden treasures, or looking after magical creatures like unicorns. Most of the time, dragons are in stories or movies, but some people believe they used to exist a very long time ago.