From Pathfinder Bestiary, which isn't enabled.

Web Lurker Deadfall

HAZARD 3

Stealth +13 DC 23 Stealth

Description A web tripwire lets loose a bundle of boulders that fall on all targets within a 10-foot square.

Disable Survival (trained) or Thievery (expert) DC 20 to rearrange the webbing.

AC 19; Fort +9, Ref +9

HP 10 (BT 5)

Deadfall

Trigger A creature steps into the square with the web tripwire.

Effect All creatures in the trap's 10-foot square take 2d6 bludgeoning damage (DC 20 basic Reflex save).

Pathfinder BestiaryOGL