Hestriviniaas

Telepathy 100 feet (aura, magical) — A monster with telepathy can communicate mentally with any creatures within the listed radius, as long as they share a language. This doesn't give any special access to their thoughts, and communicates no more information than normal speech would.

Entropy Sense (Imprecise) 60 feet (divine, prediction) — Hestriviniaas can anticipate the most likely presence of a creature through a supernatural insight into chaotic probabilities and chance. This grants it the ability to sense creatures within the listed range.

A creature under the effects of Veil of Privacy or that is otherwise shielded from divinations and predictions cannot be noticed via entropy sense.

Constant Spells — A constant spell affects the monster without the monster needing to cast it, and its duration is unlimited. If a constant spell gets counteracted, the monster can reactivate it by spending the normal spellcasting actions the spell requires.

+1 Status to All Saves vs. Magic —

Fast Healing 15 — A monster with this ability regains the given number of Hit Points each round at the beginning of its turn.

Attack of Opportunity —

Protean Anatomy 25 (divine) — Hestriviniaas' vital organs shift and change shape and position constantly. Immediately after the Hestriviniaas takes acid, electricity, or sonic damage, it gains the listed amount of resistance to that damage type.

This lasts for 1 hour or until the next time the protean takes damage of one of the other types (in which case its resistance changes to match that type), whichever comes first. The keketar is immune to polymorph effects unless it is a willing target.

If Blinded or Deafened, the keketar automatically recovers at the end of its next turn as new sensory organs grow to replace the compromised ones.

Spatial Riptide (aura, divine) — 30 feet. A creature using a teleportation ability within the aura or arriving in it via teleportation must succeed at a DC 45 Fortitude save or wink out of existence for 1d4 rounds before completing the teleport. The creature can't act, sense anything, or be targeted. On a successful save, the creature completes the teleport normally but is Stunned 1.

Keketars are immune to this effect.

Change Shape (concentrate, divine, polymorph) — Hestriviniaas can take the appearance of any Gargantuan or smaller creature. This doesn't change its Speed or its attack and damage bonuses with its Strikes, but might change the damage type its Strikes deal.

The monster changes its shape indefinitely. It can use this action again to return to its natural shape or adopt a new shape. Unless otherwise noted, a monster cannot use Change Shape to appear as a specific individual. Using Change Shape counts as creating a disguise for the Impersonate use of Deception. The monster's transformation automatically defeats Perception DCs to determine whether the creature is a member of the ancestry or creature type into which it transformed, and it gains a +4 status bonus to its Deception DC to prevent others from seeing through its disguise. Change Shape abilities specify what shapes the monster can adopt. The monster doesn't gain any special abilities of the new shape, only its physical form. For example, in each shape, it replaces its normal Speeds and Strikes, and might potentially change its senses or size. Any changes are listed in its stat block.

Constrict — 2d12+21 bludgeoning damage, DC 44 Fortitude

The monster deals the listed amount of damage to any number of creatures Grabbed or Restrained by it. Each of those creatures can attempt a basic Fortitude save with the listed DC.

Reshape Reality (concentrate, divine) — When Hestriviniaas casts Mirage, it infuses the illusion with quasi-real substance. Creatures that do not disbelieve the illusion treat structures and terrain created through the spell as though they were real, ascending illusory stairs, becoming trapped by illusory quicksand, and so on.

Warpwave Strike (divine) — A creature struck by Hestriviniaas' jaws or claw Strike must succeed at a DC 45 Fortitude save or be subject to a Warpwave.

Grab —