Sprintfang
Beast -- Medium -- Ground-level ruin debris, scrub terrain, root-tangled forest floor
It came from under the slab, not from above. I had been watching the ceiling for ten minutes because of the webs on the stairs and I was watching the wrong surface. The bite was not painful immediately, which I understand is typical. The painful part came later, in stages, over about four hours, and the stages were well-documented by the time we reached the settlement. The medic said I was lucky it was a small one.
-- field incident report, interior salvage circuit, early season
Ecology
The Sprintfang occupies the same broad ecological niche as its larger relative the Vaultstalker but operates entirely at ground level. It is a medium-bodied ambush predator built for the gap between things: the space under a fallen beam, the cavity behind a displaced wall section, the compressed debris layer at the base of a ruin mound. Where the Vaultstalker owns the ceiling, the Sprintfang owns the floor, and in environments where both are present they do not compete -- the Vaultstalker takes larger prey from above while the Sprintfang takes the smaller traffic that moves along the ground beneath the web-layer.
The speed differential between a Sprintfang at rest and a Sprintfang in motion is the source of its colloquial name. The acceleration from ambush position to strike is faster than reflex can process at close range; the animal's leg architecture appears to use a stored-tension release mechanism rather than continuous muscular effort, which is why the approach is silent and why the strike arrives without the visual warning of coiling or tensing. The eight eyes are forward-facing enough to give good binocular depth perception at close range, and the sensory arrangement that allows it to navigate by vibration through dense root-and-debris terrain means it locates prey by movement signature before it has visual contact.
The venom is not immediately incapacitating. The initial dose causes local tissue disruption and the systemic effect builds over several hours. This matters ecologically because the Sprintfang does not wait by its prey after the first bite -- it withdraws and follows at a distance, tracking by the distinctive vibration pattern of a large animal that is beginning to experience the venom's effects. Inexperienced travelers who are bitten and feel fine often make the mistake of pressing on; the animal simply presses on with them.
Sprintfangs are solitary except during the brief pairing season. Juveniles disperse early and establish territories quickly. A ruin complex that shows no signs of Vaultstalker occupancy but has active Sprintfang sign is typically one that has been recently disturbed -- something drove out or killed the apex web-builder, and the smaller animals are moving into the cleared space.
Stat block
| AC | HP | Speed | Initiative |
|---|---|---|---|
| 13 | 11 (2d8 + 2) | 40 ft., Climb 40 ft. | +3 (13) |
| STR | DEX | CON | INT | WIS | CHA |
|---|---|---|---|---|---|
| 12 (+1) | 16 (+3) | 13 (+1) | 3 (-4) | 12 (+1) | 4 (-3) |
Skills Perception +3, Stealth +7
Senses Blindsight 10 ft., Darkvision 60 ft.; Passive Perception 13
Languages None
CR 1/4 (XP 50; PB +2)
The Sprintfang can climb difficult surfaces, including along ceilings, without making an ability check. Melee Attack Roll: +5, reach 5 ft. Hit: 5 (1d4 + 3) Piercing damage plus 5 (2d4) Poison damage.Spider Climb
Bite
Encounter use
The Sprintfang's primary value as an encounter element is the delayed venom -- use it to create a clock. The initial bite deals modest damage; the real pressure is the ticking systemic effect that will become serious in a few hours. A party that dismisses the encounter because they feel fine has made a problem for later. In combat, the animal strikes once from ambush and withdraws to Stealth (its +7 makes this credible even in partial cover); it does not stand and fight. A second strike follows when an opportunity presents itself. Forcing a target to stay mobile while the venom builds is the predator's actual strategy, not the bite itself.
Salvage
The venom sacs yield one application of contact poison per specimen with a DC 12 WIS (Medicine) check. The eyes are structurally similar to Vaultstalker eyes but smaller; they have some value as optical components in close-range Lattice sensor work. A skilled trapper who has taken several Sprintfangs from the same area can infer the health of the local Vaultstalker population from the territory density -- dense Sprintfang occupation without web-layer signs above indicates the apex predator is absent, which is either an opportunity or a warning depending on what removed it.