This is a deformed or ugly child that had been left by fairies in exchange for a more attractive one. According to legend fairies could only snatch infants before they were christened. Commonly changelings were frequently thought to be senile fairies disguised as infants, and in comparative recent times both children and adults accused of being changelings were put to death. In 1894, a young woman in Clonmel in Ireland was accused by her husband and family of being a changeling and burned alive. A.G.H.
Source: 62, 41.