An umber hulk is a monster in NetHack and the sole member of the U umber hulk monster class. It one of the few monsters that can tunnel naturally through rock, a trait it shares with rock moles and woodchucks. It also has a unique, non-reflectable gaze attack that can confuse anything they glare at, including itself if a mirror is applied towards it.
Umber hulks are carnivorous, but also gain nutrition when tunneling; they are not metallivores like rock moles, though.
Umber hulks are the strongest tunneling monster encountered in the main dungeon, and move twice as fast as rock moles, though they are still much slower than even an unhasted player. Blinding yourself will protect you completely from the gaze of a hostile umber hulk; confusing it by applying a mirror also makes it somewhat less likely to turn that gaze on you. However, it can still hit decently hard.
Umber hulks are generally utilized as pets or polyforms for their natural tunneling ability—tame umber hulks combined with a magic whistle can easily eat a path through large maze levels such as Gehennom without requiring additional resources, such as the high power cost of a spell of dig, the valuable charges of a wand of digging, or bearing the weight of a pick-axe or dwarvish mattock. Hostile umber hulks can also be useful for tunneling purposes, but care must be taken to avoid becoming confused or killing them.
- Huh? That doesn't look like you!
- You applied a mirror to yourself while polymorphed into an umber hulk.
An umber hulk is an insectoid monster originating from Dungeons & Dragons. It has mandibles, exoskeleton and antennae like a beetle, but two limbs like a primate, and walks in a semi-erect manner similar to a gorilla. It has four eyes—two small and two large—and uses them to confuse unfortunate creatures that see all four at once.
Umber hulks are powerful subterranean predators whose
iron-like claws allow them to burrow through solid stone in
search of prey. They are tremendously strong; muscles bulge
beneath their thick, scaly hides and their powerful arms and
legs all end in great claws.