Cultist collector

A B/X compatible monster inspired by this image. Which might actually be intended for an RPG sourcebook, the artist has done work for Pathfinder. It's probably intended to be a cultist who is a collector, but I choose to read it as a collector of cultists. Bits of cultists, anyway.

The Collector is a summonable intelligent undead creature typically used by cult leaders to punish followers. It loves to hunt and inspire fear in its prey, so it turns the killing into a chase drawn out over hours or days. When the prey is too exhausted to run any further, the Collector will saw their hands off to keep. Then it torments them with its spears until they die.

When first summoned, the Collector is just a cloud of mist. In that form, it can inflict nightmares on a sleeping victim, gradually using their fear to manifest itself in a physical form. From that point it can take mist form at will and uses it for fast travel. In a chase, the prey finds the Collector manifesting ahead of them when they run in any direction other than the one the Collector wants. If the prey loses their fear of the Collector, it has only its stored reserve of fear to call on. When that's used up, it can no longer manifest physically.

The Collector enjoys its job, and even while bound will usually respond to summonings to see if there's another hunt to be had after this one.

AC 9 [13], HD 5 (23HP), Att 1 x spear (1d6), THAC0 12 [+5], MV 120' (40'/100' in mist form), SV 10 11 12 13 14 (F5), ML 8, AL Chaotic, XP 550, TT - (1d4-1 magic items)

Specials:

Undead: Make no noise, until they attack. Immune to effects that affect living creatures (e.g. poison). Immune to mind-affecting or mind-reading spells (e.g. charm, hold, sleep).

Holy undead: Cannot be turned by someone of the same religion as the summoner.

Mist form: The Collector can transform into mist or back as a standard action.