When did Sauron acquire fellbeasts?

Question

I am focusing on the fellbeasts acting as Nazgûl mount.

What are fellbeasts and when did Sauron acquire them? Are they Sauron's own creation or did he collaborate with them? Do they appear in any books or stories by Tolkien other than The Two Towers and Return of the King?

Answer 1

I can't believe that Mark Olson found seven quotes for his answer but didn't give the most important one. Since I could find only partial versions of that passage online, I had to type in the full passage manually from The Return of the King, Book V, Chapter 6, "The Battle of the Pelennor Fields":

The great shadow descended like a falling cloud. And behold! it was a winged creature: if bird, it was 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, whose kind, lingering in forgotten mountains cold beneath the Moon, outstayed their day, and in hideous eyrie bred this last untimely brood, apt to evil. And the Dark Lord took it, and nursed it with fell meats, until it grew beyond the measure of all other things that fly; and he gave it to his servant to be his steed. Down, down it came, and then, folding its fingered webs, it gave a croaking cry, and settled upon the body of Snowmane, digging in its claws, stooping its long naked neck.

This passage is ambiguous whether there were at least nine such fellbeasts, one for each of the Nazgûl plus spares, or only one that was ridden only by the Witch-king, with the other Nazgûl riding lesser flying creatures such as corrupted giant eagles or baby dragons. Adult dragons would probably have been much larger than the fell beast.

From the Fell Beasts page on Tolkien Gateway:

While the exact origin of the beasts is unknown, they were likely bred by Sauron from a creature of the Elder Days to supply the Nazgûl with steeds.¹

¹ _{J.R.R. Tolkien, The Lord of the Rings, The Return of the King, "The Battle of the Pelennor Fields"}

Asked about the nature of the "steed of the Witch-king", Tolkien replied that the fell beast was not intended to be pterodactylic, but hesitantly acknowledged that it resembles a pterosaur and may have been a survivor of older geological eras.⁵

⁵ _{J.R.R. Tolkien; Humphrey Carpenter, Christopher Tolkien (eds.), The Letters of J.R.R. Tolkien, Letter 211, (dated 14 October 1958)}

I would guess that in the Elder Days Morgoth bred the wingless dragons like Glaurung the Golden from something like pythons or crocodiles, and then bred the wingless dragons with members of the fell beast's species to produce the flying winged dragons.

Or possibly Morgoth bred the first flying dragons with something else to produce the first fell beasts, intended to be smaller and less dangerous but more numerous than the winged dragons, but the fell beasts did not multiply and afflict people as much as Morgoth intended.

And if I had to classify the fell beast ridden by the Witch-king I would describe it as a "terror dactyl".

Answer 2

A "fell beast" is not a specific type of animal. "Fell" is a somewhat archaic work meaning "fierce", "deadly", or "terrible" -- basically, pretty any dangerous animal can be a "fell beast."

In LotR, Tolkien uses it twice:

Under the boughs of Mirkwood there was deadly strife of Elves and Men and fell beasts.

Could be pretty much anything, really. Wolves? Bears? Spiders, even, though "beast" usually means a "mammal."

But thereupon Éomer rode up in haste, and with him came the knights of the household that still lived and had now mastered their horses. They looked in wonder at the carcass of the fell beast that lay there: and their steeds would not go near.

Here it's the flying reptile that the head Nazgûl was riding.

Where did they come from? It looks like they were already around and Sauron gathered them in. (You'll remember that the events of The Hobbit were set in train because Gandalf feared the Sauron would find a way to use Smaug (no creature of Sauron's) against Elves, Dwarves, and Men.

Among many cares he [Gandalf] was troubled in mind by the perilous state of the North; because he knew then already that Sauron was plotting war, and intended, as soon as he felt strong enough, to attack Rivendell. But to resist any attempt from the East to regain the lands of Angmar and the northern passes in the mountains there were now only the Dwarves of the Iron Hills. And beyond them lay the desolation of the Dragon. The Dragon Sauron might use with terrible effect.

So, as Gandalf says:

'Alas! Mordor draws all wicked things, and the Dark Power was bending all its will to gather them there.

Sauron pulled in "naturally occurring" beasts (many fashioned by Morgoth, no doubt) and perhaps made them more dangerous.

Going earlier to The Silmarillion, Oromë the Vala is

...a hunter of monsters and fell beasts, and he delights in horses and in hounds;

In Beleriand, Dwarves reported that

'There are fell beasts ...in the land east of the mountains, and your ancient kindred that dwell there are flying from the plains to the hills.' And ere long the evil creatures came even to Beleriand, over passes in the mountains, or up from the south through the dark forests. Wolves there were, or creatures that walked in wolf-shapes, and other fell beings of shadow;

Later, Sauron apparently added malevolent spirits to ordinary wolves:

Therefore and army was sent against him under the command of Sauron; and Sauron brought werewolves, fell beasts inhabited by dreadful spirits that he had imprisoned in their bodies.