From Pathfinder #175: Broken Tusk Moon, which isn't enabled.

Hail of Razor Stones

HAZARD 1

MECHANICAL TRAP

Stealth +11 (trained)

Description When a concealed cord is tripped, several sharp stones fall onto the square containing the cord.

Disable DC 18 Thievery (trained) to safely cut the trip cord

AC 16; Fort +9, Ref +5

Hardness 8, HP 32 (BT 16); Immunities critical hits, precision

Deadfall

Trigger A creature walks into the square containing the trip cord

Effect Falling rocks deal 4d8 slashing damage (DC 19 basic Reflex) to any creature in the square, possibly pinning them to the ground. On a failed save, the creature falls Prone; on a critical failure, the creature is Immobilized (DC 17 to Escape).

An adjacent creature can attempt a DC 19 Athletics check to shove the rocks aside to free an immobilized creature.

Pathfinder #175: Broken Tusk MoonOGL