Fell beast (Middle-earth)

In J. R. R. Tolkien's fantasy novel The Lord of the Rings, "fell beast" is the author's description of the flying creatures on which the Ringwraiths rode after being unhorsed at the Ford of Bruinen. The creatures are especially prominent during the Battle of the Pelennor Fields, where the Witch-king of Angmar, the Lord of the Nazgûl, rides his in battle against King Théoden of Rohan.

Naming
Although Tolkien called the creatures Nazgûl-birds in a private letter while comparing them to aircraft,, they are never named in the text of The Lord of the Rings, most often being described using the adjective "fell" in its archaic sense of "evil" or "grim". Tolkien also uses the word "fell" throughout the novel to describe a variety of other things.

Description and origin
In book V, chapter 6 of The Lord of the Rings, Tolkien describes the Witch-king's mount thus: "'...it was a winged creature: if bird, then greater than all other birds, and it was naked, and neither quill nor feather did it bear, and its vast pinions were as webs of hide between horned fingers; and it stank. A creature of an older world maybe it was....'" A few paragraphs later it is said to attack with "beak and claw".

Tolkien once wrote that he "did not intend the steed of the Witch-king to be what is now called a 'pterodactyl'", while acknowledging that it was "obviously ... pterodactylic and owes much" to the "new ... mythology of the 'Prehistoric'", and might even be "a last survivor of older geological eras."

1978 cartoon
In Ralph Bakshi's 1978 animated version of The Lord of the Rings, one of the Nazgûl, is shown riding a fell beast.

1980 TV special
In the Rankin-Bass 1980 animated version of The Return of the King, the Nazgûl ride winged horses, although the Nazgûl Lord does ride a bird-like creature when he confronts Éowyn.

The Lord of the Rings film trilogy
In Peter Jackson's film trilogy based on The Lord of the Rings, the fell beasts are depicted as being pterosaur-like creatures; with slightly draconic features, and all nine Nazgûl are visible onscreen riding them.

Jackson's fell beasts differ from Tolkien's description in that they do not have beaks but have very sharp teeth.

Their role in the film is explained then in the book, used by the Nazgûl in battle more extensively then and caused great destruction.

As confirmed in the films' audio commentary, the design of the fell beasts was based largely on illustrations by the popular Middle-earth artist John Howe.