Trosip

A trosip is a dark gray tuft of fluff, a dust bunny, lost among the ordinary dust of any cave, dungeon or house.

Trosips go only after sleepers, drawn by body heat. They feel motion and vibration within 60 feet, ignoring invisibility and similar magic, and freeze if anyone in range is awake. Still, they look like plain dust and are effectively invisible, though detect invisibility magic reveals them, and cats and some other animals see them. Their movement makes no sound 95% of the time.

When they snuggle onto a victim, it saves vs. paralyzation, gaining only magical protection bonuses. Failure means it suffocates in its sleep in 1d4+1 rounds, after which the trosips slip off the cooling corpse back into the dust. Success means the sleeper wakes and swats them away; they cannot travel far but dart off fast, usually vanishing before the victim is fully awake, leaving only breathlessness and the memory of a smothering nightmare.

Four trosips are needed per man-sized victim, so 24 could assault six sleeping humans. If more than twelve gang up on one target, it must succeed on two saves to live. Babies, small children and invalids are most at risk.

Trosips are never alone; finding one means others are close. A noted naturalist first studied them by magically hiding himself to watch them hunt. Scholars say trosip; common folk say death dust or breath-stealers. Assassins sometimes use them.

Unchecked, one trosip in a house becomes 24 or more within days. They live on sleepers' warmth and on crumbs and dirt, and would make fine housecleaners if they were not so lethal. Fear of them made the frontier coast obsessively tidy, and disease there has dropped sharply as a side effect.