Changelings
A changeling is basically a fairy child, or a type of Fae infant that has been put in the place of a human infant. According to the folklore of various cultures in Europe, trolls, fairies, or elves, would steal a human child, and replace it with one of their own, or worse, a “stock” which was basically a piece of wood or mannequin that has a spell upon it to make it look like a child. If it is a “stock” it will gradually deteriorate; or grow sickly and die. If it is a troll, or some other type of fairy, it may grow older and still look like a human, or grow much, much uglier, have screaming fits, bite, have unnaturally large appetites, difficulty moving, or other unpleasant traits. There are actual medieval records of changeling children, which are the oldest known origins of the changeling in folklore.
Supported by those who believe that fairies were actually once a conquered race, is the theory that changeling babies were once the offspring of this mysterious race, that had been replaced in the night. The “fairies” would replace a healthy child with one of their own, sickly offspring. This is a plausible theory; as the race of “fairies” would have sickly children over a time from repeated inbreeding, in an attempt to retain the blood of their own race. Other reasons the fairies might take a human child are to spare their own children from the Tithe; a tribute to the devil that must be paid by the fairies every seven years. Other reasons for replacing a human child are the folklore beliefs that trolls and fairies found human children very beautiful, and the desire to own a human slave, or have the love of a human child. Or, simply the desire to do harm to a human who may have done something to spite the fairies.
Some legends instruct that treating a changeling child cruelly will result in the return of a changeling child; such as bathing in scalding water, holding it over a hot stove, or putting it in an oven. Naturally there are several medieval accounts of women killing their children in ovens. Real children were sometimes mistaken to be changelings, and often abused or murdered. For example, a woman in 1826 was acquitted of murder charges when she told the courts the courts that she was not trying to drown her son, but instead drive the fairy out. In the 1890’s Bridget Cleary was murdered by her husband and several relatives. After she had suffered pneumonia, and recovered her husband accused her of being a changeling. They were convicted, but charged only with manslaughter.