Tiberolith

Tiberoliths are crude but very effective constructs, the primitive antecedents of the golems that PCs know today.  This is apparent in their stone construction (hence the “-lith” in the name), the use of vegetable sinews, the strange (al?)chemistry of acids and electricity that power them, and their rudimentary protection against spells.  Tiberoliths might be all that is left of an ancient civilization or even the key to unlocking it…assuming it doesn't smash you to pieces first.

To open a gate to another world,  adventurers must complete a ritual in the center of a henge—the core component of which involves tying a willing participant onto a stone altar.  Once the final knot is tied and the ritual begun, several of the henge’s half-sunken stones suddenly pull themselves out of the ground and attack.  Apparently the rites to quiet the site’s tiberoliths did not survive with the rest of the ritual.

An ancient society’s constructs all run on the same primitive dynamo.  In order to activate a walking tower, adventurers must first harvest three of the puzzle box-like contraptions from tiberoliths—ideally before they have expended all their shockwave attacks, otherwise the adventurers will have to jumpstart the dynamos with lightning.

A tarnished bronze dragon has taken up residence in the ruin of an ancient civilization.  Not keen on having his research interrupted, the dragon was pleased to discover the ruin’s tiberoliths ignore him but move with stolid efficiency to crush any humanoid intrusion.  The bronze, meanwhile, studies the ruins with interest, finding conflicting signs of both human and giant or cyclopean habitation.  In the damp ruins, the bronze’s tarnish seems to be less a spiritual metaphor than a physical reality, as its scales have turned brown and green.  The bronze pays no mind, even ignoring the steadily growing goiter it has developed that pulsates with the same blue glow as the tiberoliths…

—Pathfinder Bestiary 4 259