In his 2002 book Coraline, Neil Gaiman explores the idea of the 'other' mother (and, in this case, father too). He does so with typical flair and talent, but this is far from a new idea. Coraline was influenced by a frequently anthologised 19^th century story called The New Mother, by Lucy Clifford. In this story, the 'other' mother has glass eyes and a wooden tail, and replaces the loving kindly mother, not just temporarily, but forever, leaving the ‘naughty’ children alone and homeless in the wood. There are 120 years between these two stories, and yet they have surprising similarities. The motif is also found in other stories, such as Nicholas Fisk’s Grinny, in which a household is taken over by a mechanoid alien posing as the grandmother’s sister. There is also a slew of fairytales and fairytale retellings involving ogre mothers, mothers transformed into trees, and so on. In this paper, I explore the story device of 'the other mother', and try to unravel some of her mysteries, suggest what she represents in a story, why she is such a formidable, and yet irresistible, story construct, and what sort of ideological implications and moral imperatives her stories imply.