changelings are an element of European folklore often fairies elves or trolls would secretly exchange human infants with one of their own offspring these substituted children are known as changelings in this film however they don't exchange their children for human children instead they observe humans and shapeshift into the humans that they observe now changelings often appear sickly with distinct physical anomalies compared to the human children they replace they might be described as having unusual features such as long teeth large eyes or a frail body they are often known for their odd or malicious behavior they may be unusually quiet or cry all the time they may have strange movements or display extraordinary strength or knowledge that is inappropriate for their age