Who/What was Tom Bombadil

If memory serves me correctly, Gandalf was talking about the Balrog, so there is one of those evil things.

Originally posted by obloquy:
<STRONG>Tom isn't Tolkien's only enigma. For example, Gandalf tells us that there were evil things in the deep places beneath the mountains that were older than Sauron! Stir up any curiosity? Well, sorry, he doesn't elaborate. They remain enigmatic.</STRONG>