A Caveworm
Cave Worms were the most specialized and repellent breed of Cave Drakes. They lacked any noticeable limbs and lived their whole lives underground. Like most cave creatures, they had little pigmentation and even less eyesight, relying on the ability to "read" vibrations and a good sense of smell to locate the prey that they seized with their prehensile tongues. Because they had a constant need for calcium, the favorite food of Cave Worms was bones.
Cave Worms combined most of the least desirable characteristics of worms, being constantly covered with slimy mucous. They would eat almost anything, meat being a favorite, but roots and fungus were quite acceptable in a pinch. They did not, however, eat rock, despite persistent Dwarvish legends to the contrary. Rather, they used the six hard horns on their bony heads as drill bits to bore their way through soft or crumbling stone, sliding along on their mucous as they went. A bony ridge protectef their jaws and narrow eyes from this boring activity.
Cave Worms dwelt in the Underdeeps. Thus, they were most common in Moria, although they could be encountered in other spots where someone had been foolish enough to dig too far beneath the earth.