Changelings are Creatures from the Invisible World that have taken on the form of a Human, usually a child, while that person is carried to live among the Faeries. Elves and Pixies are most commonly the culprits, either leaving behind one of their own to grow up among mortals or leaving behind a piece of wood enchanted to look like the mortal that was stolen. Sometimes the Changeling will fake its own death or mysteriously disappear in order to rejoin its own family (now one member larger with the addition of a Human brother or sister).
There are various methods of protecting a child from being stolen: leaving open iron scissors where the child sleeps (dangerous and not recommended), placing a key on the child's blankets, turning the father's trousers inside-out and hanging them over the cradle or stringing bundles of rowan and garlic along the sides of the infant's bed. Despite the abundance of methods, however, few are employed today.
Changelings often have distinct characteristics that set them apart from their children. They may have a tail, a hunched back or a withered appearance, even if very young. They may also develop a grayish or greenish tone to their skin. A Changeling will also eat differently from a regular child. Although they can consume enormous quantities, some are very picky and occasionally refuse to eat anything but uncooked vegetables or flowers. Their hair and nails grow long quite quickly, adding to the strangeness of the Changeling's overall appearance. Perhaps the unnaturally swift growth is due to the difficulties with aligning a Human body to a Faerie passage of time.
The Fey Folk cry and laugh at inappropriate times and say unexpected and strange things. A person that speaks entirely in singsong or riddles is probably a Changeling.
Changelings have been known to try to lure their Human "family" into the hands of their Faerie family. Beware if asked to go on a moonlit walk through the woods with a family member that has been behaving strangely.
To win back your stolen family member, you should catch the Changeling and return it to the Faerie mound where it came from. If this proves impossible, you can threaten the Changeling with iron, which has the same effect on Changelings as it does on all Creatures of the Invisible World. Although in some of the old stories the Changeling is thrown on a fire or burned with a hot poker, it is unlikely that such an action would go unpunished.
Occasionally a Changeling will grow up with a mortal family and his or her odd characteristics will diminish, until even the Faerie forgets that it is not a Human. (Compare to Pixie and Elf)