Nameless Things

What Gandalf said

When Gandalf told Aragorn, Legolas and Gimli in Fangorn how he had fallen with the Balrog from the Bridge of Khazad-dûm, he described a long fall into deep water, a fight in the dark at the bottom of the world, and the Balrog's flight through tunnels far below the deepest delvings of the Dwarves. Those tunnels, he said, were not made by Durin's folk. They were gnawed by nameless things that lived in the roots of the earth, creatures older than Sauron, of which Sauron himself knew nothing, and Gandalf refused to say more of them for fear of troubling the daylight. The Balrog knew the way through their tunnels and led Gandalf up the Endless Stair to Zirakzigil, and that is the last the texts say of the deep places.

That is the whole direct statement. Its interest is in what it rules out. The nameless things are not Sauron's; he does not know them. They are older than he is in the world, which places their origin in the first ages of Arda, before the Elves awoke. They gnaw and tunnel, so they have bodies. They are many, since Gandalf speaks of them in the plural. And they are terrible enough that the wisest of the Wise would not name them.

The Watcher in the Water

The one creature of the deeps that the texts actually show is the Watcher in the Water. It lived in the stagnant lake that had formed before the West-gate of Moria when the Sirannon was dammed, and the Book of Mazarbul recorded that it had killed Óin of Balin's company some thirty years before the Fellowship came. When the Fellowship stood at the gate, pale-green luminous tentacles came out of the water, seized Frodo by the ankle, and were driven off only by Sam's knife and the company's flight into the mountain; the creature then tore down the doors and blocked the passage with fallen trees and stone. Gandalf remarked that of all the company it had reached for the Ring-bearer first.

The texts never say that the Watcher was one of the nameless things. It lived at the door of Moria rather than in the roots of the mountains, and its pool was of recent making; it may have crawled up from below, or been something else altogether. But a many-armed monster of unknown kind, older than any account of it, lurking in the dark beneath the Misty Mountains, fits Gandalf's description more closely than anything else in the books, and the Atlas places it here with that caution.

Other creatures of the dark

Several other passages gesture at creatures the Wise do not name. The Ered Gorgoroth of Beleriand held monsters and spider-creatures that had lurked there since Angband was first delved, before Ungoliant came. The Old Forest and the Barrow-downs were haunted by things older than Men. Morgoth's first fortress Utumno bred horrors in the dark that the Valar destroyed when they broke it, and some may have survived in the deep places. None of these is identified with the nameless things under Moria, and the Atlas records them only as parallels.

Fate

Unknown. Gandalf gave no sign that the nameless things had been disturbed by anything but the Balrog's passage, and there is no reason to suppose they did not remain beneath the mountains into the Fourth Age.

Undescribed, by Gandalf's deliberate choice. They tunnel through rock, so they are bodily and strong. The Watcher, if it is one of them, had many long pale-green luminous arms, a body that never fully surfaced, and enough strength to wrench great doors from their hinges.

None.

Unknown. Older than Sauron, unknown to him, and therefore not of his or presumably Morgoth's making, though the texts do not say whose making they were.

Unknown; presumed to remain in the deeps.