The stumbling horror is a monster added in dNetHack. It is part of the U class, which in dNetHack indicates an "unknown abomination". The statistics for this monster, along with wandering and shambling horrors, are randomized every game.
- The speed is anywhere from 6 to 18 (slow to fast)
- The AC is anywhere from 10 to -20
- The MR is anywhere from 0 to 100
- The alignment is anywhere from 8 to -8.
- A horror has up to 4 attacks, each with a random attack type and damage type.
- The damage types encompass almost every type in the game, excluding rider-only attacks, lycanthrope attacks, seduction (nymph or foocubus) attacks, and lethe attacks.
- Not every damage type is possible for each attack type, inclusions are mostly based on whether there is a pre-existing monster with that attack combination already.
- The size can be anything from tiny to gigantic.
- The corpse weight and nutrition will match the size, but this doesn't matter, as horrors will never leave a corpse.
- The sounds will always be a random humanoid sound.
- The horror then gets up to 17 flags of each type (resistances, resistances conveyed, movement pattern, etc.)
- The horror will never be polymorphable, always hostile, and never a werecreature.
- Any contradictory flags (such as MT_ANIMAL and MT_MINDLESS) are filtered out with one chosen.
- The horror will have a random type of internal organs, one of none, normal, or non-differentiated (homogenous) organs.
- The horror will have a level based on its attacks and flags, but always above 11.
- If the horror should have a level below 11 based on attacks and flags, the entire horror will be regenerated.