From Pathfinder Society Scenario #4-04: To Seek the Heart of Calamity, which isn't enabled.

Living Boulder (PFS 4-04)

CREATURE 2

Living boulders roll and glide through the Plane of Earth, gathering gemstones and metal shards until their surfaces resemble a ship's hull covered in barnacles. Barely more intelligent than many animals, living boulders fill much the same role on the Plane of Earth as the great herd animals found on Material Plane worlds.

Perception +6; darkvision, tremorsense (imprecise) 30 feet

Skills Athletics +8, Stealth +5 (+7 in rocky areas)

Str +4, Dex -1, Con +4, Int -4, Wis +2, Cha -1

Tremorsense 30 feet

Tremorsense allows a monster to feel the vibrations through a solid surface caused by movement. It is an imprecise sense with a limited range (listed in the ability). Tremorsense functions only if the monster is on the same surface as the subject, and only if the subject is moving along (or burrowing through) the surface.

AC 17; Fort +10, Ref +5, Will +8

HP 24; Immunities bleed, paralyzed, poison, sleep

Speed 20 feet, burrow 20 feet; earth glide

Melee Jaws +10 (unarmed), Damage 1d8+6 piercing

Earth Glide

A living boulder can Burrow through earthen matter, including rock. When it does so, it moves at its full burrow Speed, leaving no tunnels or signs of its passing.

Rolling Charge

The living boulder Strides twice, and can then make a Strike with its jaws. This jaws Strike gains Knockdown.

Pathfinder Society Scenario #4-04: To Seek the Heart of CalamityOGL