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From Pathfinder Society Scenario #2-18: The Fanciful March of Urwal, which isn't enabled.

Vermlek Centaur (3-4)

CREATURE 4
RARELARGECHAOTICDEMONEVILFIENDUNHOLY
Perception +10; darkvision
Languages Chthonian, Draconic, Empyrean, Pyric; telepathy 100 feet
Skills Acrobatics +10, Athletics +11, Deception +9, Stealth +10
Str +3, Dex +2, Con +5, Int +1, Wis +1, Cha +3
Items Light Hammer (3), Longsword
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.

AC 20 ((23 while Inhabiting a Centaur Body)); Fort +13, Ref +10, Will +7
HP 65; Weaknesses cold iron 5, holy 5, sonic 5
Recoil from Wasted Opportunities

Vermleks cannot stand the sight of a good meal presented and then swiftly taken away. Whenever a Dying creature within sight of the vermlek has its dying condition removed, the vermlek takes 1d6 mental damage.

Speed 25 feet; 40 feet (while Inhabiting a Centaur Body), 25 feet, burrow 15 feet (while not Inhabiting a Centaur Body)
Melee Jaws +14 (unarmed, unholy), Damage 2d8+5 piercing
Melee Hoof +11 (agile, unarmed, unholy), Damage 1d10+5 bludgeoning
Melee Longsword +14 (unholy, versatile p), Damage 1d8+5 slashing
Melee Light Hammer +14 (agile, thrown 20, unholy), Damage 1d6+5 bludgeoning
Melee Light Hammer +14 (agile, thrown 20, unholy), Damage 1d6+5 bludgeoning
Divine Innate Spells DC 20, attack +12; 3rd Fear, Harm
Abandon Body (manipulate)
Requirements The vermlek is Inhabiting a Centaur Body
Effect The vermlek crawls out of the body it is inhabiting, devouring much of the body's remaining flesh and regaining 15 healing Hit Points in the process. The corpse it leaves behind is little more than a husk.
Inhabit Centaur Body (manipulate)

While most vermleks inhabit Medium humanoids, Urxehl has granted this demon the ability to inhabit centaurs instead.

The vermlek crawls into the body of an adjacent dead centaur, consuming the bulk of the victim's skeleton and internal organs as it does so and cramming itself into the cavity.

The vermlek can wield weapons and use the centaur's Speed, hoof attack, and Trample ability. It also gains a +3 circumstance bonus to AC. While Inhabiting a Centaur body, a vermlek can't burrow.

It can't use this ability if it's already Inhabiting a Centaur Body.

Trample

Medium or Smaller; Hoof; DC 21 basic Reflex

The monster Strides up to double its Speed and can move through the spaces of creatures of the listed size, Trampling each creature whose space it enters. The monster can attempt to Trample the same creature only once in a single use of Trample. The monster deals the damage of the listed Strike, but trampled creatures can attempt a basic Reflex save at the listed DC (no damage on a critical success, half damage on a success, double damage on a critical failure).

Unsettling Movement (emotion, fear, mental, visual)

Whenever the vermlek Abandons a Body or Inhabits a Body, all creatures within 30 feet who can see the vermlek must succeed at a DC 20 Will save or become Frightened 1. On a critical failure, the creature is frightened 1 and Sickened 1.

Regardless of the result, creatures are immune to the same vermlek's unsettling movement for 24 hours.

Pathfinder Society Scenario #2-18: The Fanciful March of UrwalOGL