"The Man in the Moon Stayed Up Too Late" is J. R. R. Tolkien's imagined original song behind the nursery rhyme "Hey Diddle Diddle (The Cat and the Fiddle)", invented by back formation. It was first published in Yorkshire Poetry magazine in 1923, and was reused in extended form in the 1954–55 The Lord of the Rings as a song sung by Frodo Baggins in the Prancing Pony inn. The extended version was republished in the 1962 collection The Adventures of Tom Bombadil.