by Peter S. Beagle

And then I would add The Last Unicorn by Peter S. Beagle to the list a second time, in case you missed case the first time.

Peter Beagle

The screenplay is by Peter Beagle, most famous as writer of The Last Unicorn.

by Jimmy Webb of the band America

The Last Unicorn is a song written by Jimmy Webb of the band America for the 1982 fantasy film of the same name.

by Viking Press in the U.S. and in the U.K. The Bodley Head

The Last Unicorn is a fantasy novel by American author Peter S. Beagle and published in 1968, by Viking Press in the U.S. and The Bodley Head in the U.K.