Literature
Knightmare n - Level 1 Monsters
Banshee
The banshee is not dangerous in her own right but wails when there’s something deadly-dangerous nearby, so effectively provides early warning of goblins and similar.
Cold Ghost
The Cold Ghost gets to clue rooms ahead of the dungeoneer and removes all the objects. It will only leave them/put them back if gifted with an acorn, some other kind of seed, or an item of warm clothing. The dungeoneer needs to be tipped off about this before they get to the clue room, so that means either Sir Escart warning them ahead of time, a clue such as a scroll, or being informed of it by a character.
Flock of [Somewhere; location TBC],