Vaultstalker
Beast -- Large -- Collapsed structures, ruin interiors, undercroft passages
The web was not across the doorway. It was twenty feet in, where the corridor narrows before the stair. Someone had been through the door -- the footprints were there -- and had not come back. The web was intact except for one anchor thread that had been replaced recently, the new silk still bright against the grey of the rest. When we found the body it was in the ceiling, not the floor. The web was a floor too, apparently, and we had not understood that until we were already on it.
-- salvage team incident log, eastern sector ruin complex
Ecology
The Vaultstalker is a large ambush predator adapted almost entirely to enclosed structural environments. It does not build webs across open ground or in standing forest; it builds them inside: across collapsed staircases, between load-bearing columns, stretched over the debris fields that fill the lower levels of pre-Forgetting structures. The animal seems to have a particular affinity for architecture with multiple levels, which researchers attribute to the web's function as a three-dimensional hunting tool rather than a flat barrier. A Vaultstalker's web is laid to create an invisible floor: a horizontal sheet of silk, dark and semi-transparent, set at a height where a person would step without looking down.
The silk itself has properties that complicate a simple predator-prey understanding of the animal's ecology. Analysis of recovered samples shows a consistent nanite load woven into the fiber -- not at the density of an active Lattice fragment, but enough to give the silk a tensile quality that ordinary biological silk cannot match. Vaultstalker silk does not burn cleanly; it chars and partially reforms. Whether this is an evolved trait or a consequence of the animal's diet in high-Miasm ruin environments is unclear. The practical result is that the silk resists simple burning and requires sustained heat or physical destruction to neutralize.
Vaultstalkers do not compete with smaller web-building lineages for prey; they predate them as readily as anything else. A ruin complex occupied by a Vaultstalker will typically be cleared of smaller web-based predators within a seasonal cycle, which is one of the field signs experienced salvage teams look for when assessing a structure. No smaller webs means something big enough to eat their makers moved in.
The Web Walker trait -- an apparent capacity to sense vibration across the entire web simultaneously -- makes any web the Vaultstalker has laid an extension of its sensory range. Creatures that step onto a web and hold still are not invisible; they are simply not triggering the movement-response. The animal waits until the vibration pattern it reads as prey-sized distress, not prey-sized caution, before descending.
Stat block
| AC | HP | Speed | Initiative |
|---|---|---|---|
| 14 | 26 (4d10 + 4) | 30 ft., Climb 30 ft. | +3 (13) |
| STR | DEX | CON | INT | WIS | CHA |
|---|---|---|---|---|---|
| 14 (+2) | 16 (+3) | 12 (+1) | 2 (-4) | 11 (+0) | 4 (-3) |
Skills Perception +4, Stealth +7
Senses Darkvision 60 ft.; Passive Perception 14
Languages None
CR 1 (XP 200; PB +2)
The Vaultstalker can climb difficult surfaces, including along ceilings, without making an ability check. The Vaultstalker ignores movement restrictions caused by webs and knows the location of any creature in contact with the same web. Melee Attack Roll: +5, reach 5 ft. Hit: 7 (1d8 + 3) Piercing damage plus 7 (2d6) Poison damage. Dexterity Saving Throw: DC 13, one creature the Vaultstalker can see within 60 feet. Failure: The target has the Restrained condition until the web is destroyed (AC 10; HP 5; Vulnerability to Fire damage; Immunity to Poison and Psychic damage). The nanite-laced silk resists simple flame; sustained heat of an open flame held against the web for a full round destroys it regardless of HP.Spider Climb
Web Walker
Bite
Web (Recharge 5-6)
Encounter use
A Vaultstalker encounter is an architecture problem before it is a combat problem. Place the web before the players enter the space, use the Web Walker trait to give the creature perfect awareness of where they step, and let the ambush come when someone is already Restrained. The ceiling is always a possible attack vector; a creature that can Spider Climb has no reason to descend until it is ready. For groups that do not check ceilings, the first hint is the web snare from above. For groups that do, the Vaultstalker simply waits on an adjacent ceiling panel until the party's formation exposes a target it prefers.
Salvage
Vaultstalker silk harvested intact has genuine trade value. The nanite load in the fiber gives it unusual tensile properties; rope makers and armor liners in settlements with access to ruin-range silk have developed techniques for incorporating it into composite materials. A full web harvested without damage yields enough material for one length of high-quality climbing rope or equivalent. The venom sacs, if removed intact with a DC 14 WIS (Medicine) check, contain enough concentrated material for two applications of contact poison (same effect as the Bite, administered separately). Vaultstalker eyes, which have a distinctive iridescent quality from the multi-spectrum sensitivity, are occasionally used as optical components in salvaged Lattice repair work.