Cave beetle

Also known as "rock beetles," cave beetles are black, hard-shelled scavengers that live in the Deep Roads and typically consume carrion. On their own they are little more than a nuisance but an entire nest stirred by a careless passerby can become a swarm capable of stripping the flesh from a creature in a matter of minutes. A swarm is relentless and fast-moving, able to move along tunnel walls, floors, or even ceilings in pursuit of prey.

Trivia

 * Dwarves are known to roast and eat cave beetles out of the shell.