A changeling is a false baby, planted by malevolent fairies to replace a human child. the changeling looks similar to the human child who was abducted, but it is deformed and wicked (Yolen 50; Asala 128-130). Although a changeling appears as a young child, it is actually an adult fairy with thousands of years of experience (Yolen 54). Changelings often forget that they are pretending to be babies, and may exclaim and give themselves away if they see something they never have before (Yolen 50-54).
Since the changeling takes the form of a baby, which people naturally take care of, the myth explores the possibility of a helpless, innocent creature being malevolent. The idea of changelings stems out of parents’ desire to have perfect children. If a child is flawed, the parents can explain this away with the idea that their healthy, perfect baby has been stolen away by fairies.