Paleohemoth

Creature 12

rare
Huge
construct
mindless

Perception: +20; darkvision
Skills: Athletics +20; Str +7, Dex +2, Con +6, Int −5, Wis +0, Cha −5

AC: 33; Fort +26, Ref +20, Will +18
HP: 195; Weaknesses cold 10, earth 10, water 10; Resistances physical 10 (except adamantine or bludgeoning), spells 10 (except cold or earth or water)

Speed: 25 feet

Melee ◆ jaws +26 (deadly d10, magical, reach 15 feet, unarmed), Damage 3d10 + 13 piercing plus Fossilization

Fossilization (arcane, incapacitation) The first time each round a creature takes damage from the paleohemoth's jaws, the target must attempt a DC 32 Fortitude save. If it fails and has not already been slowed by this ability, it becomes Slowed 1 for 1 minute.

If the creature was already slowed by this ability, a failed save causes it to be Petrified permanently.

Reassemble ◆ The paleohemoth reorganizes its bones, increasing its reach to 25 feet and reducing its Speed to 15 feet. It can revert to its original form by taking this action again.

Source: Pathfinder Monster Core

Running this fight? Add the paleohemoth to the initiative tracker: type its name and the AC, hit points and Perception for initiative fill in, and the book button shows this stat block mid-fight.