pf2e.fyi
From Pathfinder Society Scenario #4-99: Blessings of the Forest, which isn't enabled.

Abyssal Warhound Pack Leader

CREATURE 5
UNCOMMONLARGEANIMALCHAOTICDEMONEVILFIENDUNHOLY
Perception +11; darkvision, scent (imprecise) 30 feet
Skills Acrobatics +13, Athletics +10, Intimidation +13, Survival +13 (+15 to Track)
Str +4, Dex +0, Con +5, Int -4, Wis +2, Cha +2
AC 19; Fort +14, Ref +9, Will +11
HP 95; Weaknesses cold iron 4, holy 4; Resistances acid 8
Speed 30 feet
Melee Jaws +15 (unarmed, unholy), Damage 2d8+7 piercing plus Knockdown
Caustic Drool (acid)

Caustic saliva drips from the warhound's mouth. Until the end of its turn, the abyssal warhound's jaws Strike deals an additional 2 points of acid damage on a successful attack, or 4 points on a critical success.

Effect: Caustic Drool

Hunting Call (auditory)

The pack leader throws its head back and lets out a bone-chilling howl. All abyssal warhounds and pack leaders with 30 feet that hear the call immediately activate their Caustic Drool ability as a free action. A creature that benefits from this effect becomes immune to this creature's call for one minute.

Shake
Requirements The abyssal warhound's Caustic Drool ability is active
Effect The warhound shakes its head, splattering nearby creatures with caustic saliva. All creatures within 10 feet of the warhound take 3d4 acid damage (DC 19 basic Reflex). Abyssal warhounds are immune to this damage.
Warning Growl (auditory, emotion, fear, mental)
Trigger A creature targets the warhound with a melee Strike
Effect The warhound Demoralizes the triggering creature and does not take a penalty for not speaking a language. The results of this check occur before resolving the triggering Strike.
Knockdown

Requirements The monster's last action was a successful Strike that lists Knockdown in its damage entry
Effect The monster attempts to Trip the creature. This attempt neither applies nor counts toward the monster's multiple attack penalty.

Pathfinder Society Scenario #4-99: Blessings of the ForestOGL