I know there is no real answer as Tolkien never spoke on the subject... but what on earth could the Nameless Things possibly be?

"Far, far below the deepest delving of the Dwarves, the world is gnawed by nameless things. Even Sauron knows them not. They are older than he."

We have no real answer on what these Nameless Things are. But Sauron is a Maiar, one of the Ainur, and "they are older than he".

How is that possible? Weren't the Ainur the first creations of Eru? How could anything other than Eru himself be older than them? It baffles me, and I've always wondered what they are.

I know there is not a straight forward objectively correct answer. I'm really looking for theories. Were they a truly first to be created race that turned evil, then Eru started over and created the Ainur? There is nothing in Tolkien's works to suggest this, and since Eru was an omnipotent, omniscient deity, this seems unlikely. He couldn't make a mistake if he is a totally sovereign and all-powerful god. Were they fallen Ainur? Again, no evidence of that, but this seems the best theory, however unlikely. Were they a byproduct of Melkor's corruption of the song of the Ainur? That would be impossible, because they came before Sauron. I just don't know man.

It blows my mind to think on this. An unsolvable puzzle. But what is your best theory? There are no right or wrong answers in this thread, I'd just like to see what people think about them. IMO, this is the greatest mystery in the Tolkien-verse, even more than Tom Bombadil's identity (I think he was a Maiar, or some special form of Valar). The Nameless Things are the great mystery for me.

What do you think? Again, no right or wrong answers. Be sparing with your downvotes and generous with your upvotes for all answers!