“Umber hulks are powerful subterranean predators whose ironlike claws allow them to burrow through solid stone in search of prey.
Umber hulks are tremendously strong, standing nearly 8 feet tall and over 5 feet wide. Muscles bulge beneath their thick, scaly hides and their powerful arms and legs all carry great claws. They have no necks to speak of, but the head features a powerful maw with rows of triangular teeth and 8-inch mandibles capable of biting through any hide or bone. Most peculiar of all are the four round eyes, spaced evenly across each umber hulk’s forehead. Umber hulks are black, shading to a lighter shade of yellowish gray on the front. Their eyes are mere blackened dots each the size of a small coin. Umber hulks have their own language.” The Monstrous Manual, 2nd Edition