Living Magma

Molten Form (fire) — Any creature that hits the living magma with an unarmed Strike or otherwise touches it takes 10 fire damage. If a gallon or more of water touches the living magma, or if it's affected by a water effect, its outer layer of lava hardens to a rocky shell, deactivating its molten form and imposing weakness 15 to bludgeoning damage. Molten form reactivates if the living magma swims in lava for 1 minute.

Trap Weapon (fire) — Frequency once per round

Trigger A creature hits the living magma with a melee weapon
Effect The living magma attempts an Athletics check against the triggering creature's Athletics DC. On a success, the living magma traps the weapon in its body and pulls it from the attacker's grasp. A creature can Interact to retrieve the weapon, but the attempt fails unless the creature succeeds at an Athletics check against the living magma's Fortitude DC (typically 36). If the living magma uses Engulf, it also absorbs all trapped weapons, rendering them unreachable until it dies.

Engulf — DC 33 Reflex, 2d10 bludgeoning plus 4d6 fire damage, Escape, Rupture 25

The monster Strides up to double its Speed and can move through the spaces of any creatures in its path. Any creature of the monster's size or smaller whose space the monster moves through can attempt a Reflex save with the listed DC to avoid being engulfed. A creature unable to act automatically critically fails this save. If a creature succeeds at its save, it can choose to be either pushed aside (out of the monster's path) or pushed in front of the monster to the end of the monster's movement. The monster can attempt to Engulf the same creature only once in a single use of Engulf. The monster can contain as many creatures as can fit in its space.

A creature that fails its save is pulled into the monster's body. It is Grabbed, is Slowed 1, and has to hold its breath or start suffocating. The creature takes the listed amount of damage when first engulfed and at the end of each of its turns while it's engulfed. An engulfed creature can get free by Escaping against the listed escape DC. An engulfed creature can attack the monster engulfing it, but only with unarmed attacks or with weapons of light Bulk or less. The engulfing creature is Off-Guard against the attack. If the monster takes piercing or slashing damage equaling or exceeding the listed Rupture value from a single attack or spell, the engulfed creature cuts itself free.
Effect: Engulf and Swallow Whole

A creature that gets free by either method can immediately breathe and exits the swallowing monster's space.

If the monster dies, all creatures it has engulfed are automatically released as the monster's form loses cohesion.

Launch Lava (fire) — The living magma hurls an exploding glob of lava up to 120 feet. Each creature in a 10-foot burst takes 7d6 fire damage (DC 33 Reflex save).

Reignite (fire) —

Volcanic Heat (aura, fire) — 40 feet. Any creature that enters or starts its turn in the aura takes 15 fire damage (DC 33 Fortitude save). A creature that fails its save is also Enfeebled 1 until it's no longer in the aura.