The Nameless Things were a bizarre and interesting species of creature found underneath the Misty Mountains. Gandalf said in the Two Towers

Far, far below the deepest delvings of the Dwarves, the world is gnawed by nameless things.

Through the gnawed tunnels that the Nameless Things delved Gandalf pursued the Balrog.

What were the Nameless Things?Edit

There are many theories concerning this. The term 'Nameless Things' might be a metaphor for natural earth processes that formed underground tunnels.

There are five major theories concerning their origin.

1. The Nameless Things were originally Ainur who entered Arda before Sauron arrived, hence the phrase, "Sauron knows them not for they are older than him", meaning they lived in the world longer than Sauron.
2. They were specific spirits like Tom Bombadil and his wife Goldberry.
3. The Nameless Things were species from the void, much as Ungoliant. They were most likely caused by Melkor's independent singing in the Music of the Ainur.
4. The Nameless Things were among the creatures created in Utumno by the Dark Powers .
5. Concept art for the film version of The Two Towers, showed the Nameless Things as cephalopod-like amphibious shiny translucent beings, and there was also going to be concept art for the slimy, black Balrog before he regains his fire, but these scenes were cut from even the script.

In The HobbitEdit

Some of these caves, too, go back in their beginnings to ages before the goblins, who only widened them and joined them up with passages, and the original owners are still in odd corners, slinking and nosing about.

In The Hobbit it is mentioned that the goblins were not the original owners of Goblin-town. These original owners do not appear to be any of the known races of Middle-Earth and are likely the same species as the Namless Things. Gollum might have originally have been meant to have been one, since they were said to still be in the passages in certain areas, before Tolkien decied he was originally a Hobbit.