Changelings are mythical creatures found in folklore, particularly in European traditions. They are often described as fairy children left in place of human babies. According to legend, fairies would steal a human child and replace it with a changeling, which might appear similar but often had strange behaviors or characteristics. These tales served as explanations for unexplained illnesses or developmental issues in children. Parents believed that their real child was taken to the fairy realm, while the changeling was a deceptive substitute. The stories of changelings highlight the fears and mysteries surrounding childhood and the unknown in ancient times.