In Irish folklore, a changeling is a fairy child that was left in place of a human child stolen by the fae. Changelings often appear exactly like a human children but with strange differences such as long teeth, a full beard, uncanny intelligence and odd behavior. Jinn from Arabic folklore are also known to steal human children and replace them with changelings. Image: Titania and the Changeling Child (detail) by John Anster Fitzgerald, 1832-1906