Today’s monster is converted from the “hexmute” found in GURPS: Creatures of the Night by Scott Paul Maykrantz.
Painsoppers are strange humanoids who live on pain. Usually encountered in groups of 3 to 10, they are indistinguishable from normal humans except for their irises, which are pure black, and the fact that they never speak. They always wear nondescript clothes, and often hang around at public executions, hospitals, and car accidents, but disperse as soon as authorities arrive. Some do strange, depraved things while draining their victims, such as drool, smile widely, kiss each other, or even rub themselves.
However, painsoppers are natural bottom-feeders, and almost never engage in combat. If approached, they run. Moreover, they can magically merge with shadows and move invisibly to re-emerge up to 500 yards away, and can do this as often as they wish.
A painsopper will die if he or she does not spend at least one hour per week in the presence of a sapient humanoid who is in mortal or near-mortal pain. While a nearby humanoid is in serious pain, any painsopper nearby regains half as many Hit Points (or appropriate Health score) as the humanoid loses. However, every painsopper loses one tenth of his or her Hit Points per day. To increase its feeding times, it will magically stave off death in its victim; each victim reduced to 0 HP may make a Constitution check (or other appropriate roll) to stay conscious at 1 HP, and makes death saving throws at +2.
Painsoppers normally live as transients on the far outskirts of society. Thanks to their shadow step, they have no need to stay within civilization; instead, they will create the barest semblance of a homeless commune in an out-of-the-way spot and stay there between “feedings.” Nobody knows what they get up to there; anyone approaching will prompt the painsoppers to flee.
Legends say that anyone who spends inordinate amounts of time near a place of many deaths, like a battlefield or a hospital, eventually becomes a painsopper. Others claim it’s a curse, or even the effects of a drug. Nobody can say for sure.