"with huge black eyes like some changeling."
The Changeling (1780), by Johann Heinrich Füssli
Public DomainThe Changeling (1780), by Johann Heinrich Füssli - Credit: Kunsthaus Zürich

A changeling is a creature found in European folklore and folk religion. It is typically described as being the offspring of a fairy, troll, elf or other mythical creature that has been secretly left in the place of a human child. Sometimes the term is also used to refer to the child who was taken.

 

Painting by John Bauer of two trolls with a human child they have raised (1913)
Public DomainPainting by John Bauer of two trolls with a human child they have raised (1913) - Credit: Wikimedia Commons