Wikipedia
Mossycoat
"Mossycoat" is a fairy tale collected by Katherine M. Briggs and Ruth I. Tongue in Folktales of England. It appears in A Book of British Fairy Tales by Alan Garner. The story known by folklorists was told was Taimi Boswell, a gypsy, at Oswaldtwistle, Lancashire, January 9, 1915.
It is Aarne-Thompson type 510B, unnatural love. Others of this type include Donkeyskin, Catskin, Allerleirauh, The King who Wished to Marry His Daughter, The She-Bear, Tattercoats, Cap O' Rushes, The Princess That Wore A Rabbit-Skin Dress, and The Bear.