Whenever a beastmaster cultist and one of their animal allies are adjacent to the same foe, they both count as flanking that foe regardless of their actual positions.

Beast Training

The beastmaster cultist blows on her divine whistle, riling up the nearby beasts, granting a +1 status bonus to attacks and damage to all allied animals within 60 feet for one round.

Enraging Whistle

Trained Beastmaster Cultist - chaotic, evil, orc

The beastmaster cultist blows on her divine whistle, riling up the nearby beasts, granting a +1 status bonus to attacks and damage to all allied animals within 60 feet for one round.
@UUID[Compendium.pf2e.bestiary-effects.Item.Effect: Enraging Whistle]

Trained Beastmaster Cultist

Mace

Shortbow

Level

Rarity

Traits

Pathfinder 2e creature: Trained Beastmaster Cultist