Sooterkin

A sooterkin is a fabled small creature about the size of a mouse that certain women were believed to have been capable of giving birth to. The origin of this initially jocular fantasy lies in the 18th century, and some eminent physicians of the day considered it factual. It is attributed to a tendency of Dutch women to frequently sit on stoves or use them under their petticoats to keep warm, hence causing the breeding of a small kind of animal that would mature and be born.