Overview
A changeling, also historically referred to as an auf or oaf, is a human-like creature found in folklore throughout Europe. A changeling was believed to be a fairy that had been left in place of a human (typically a child) stolen by other fairies.
Description
A changeling is typically identifiable via several traits, which vary from culture to culture.
In Irish legend, a fairy child may appear sickly and will not grow in size like a normal child, and may have notable physical characteristics such as a beard or long teeth. They may also display intelligence far beyond their apparent years and possess uncanny insight. A common way that a changeling could identify itself is through displaying unusual behaviour when it thinks it is alone, such as jumping about, dancing or playing an instrument – though this last example is found only within Irish and Scottish legend.
"A human child might be taken due to many factors: to act as a servant, the love of a human child, or malice. Most often, it was thought that fairies exchanged the children. In rare cases, the very elderly of the fairy people would be exchanged in the place of a human baby so that the old fairy could live in comfort, coddled by its human parents. Simple charms such as an inverted coat or open iron scissors left where the child sleeps were thought to ward them off; other measures included a constant watch over the child."
From Wikipedia (CC BY-SA 4.0).