pf2e.fyi
From Pathfinder Society Scenario #1-02: The Mosquito Witch, which isn't enabled.

Young Bloodseeker Swarm

CREATURE 3

Swarms of centipedes are dangerous indeed, ravenous carpets of skittering hunger capable of devouring a traveler whole in a matter of minutes. Some alchemists submerge whole centipedes taken from swarms in their elixirs and some mutagens, claiming such infusions increase potency, though other say this is nothing more than quackish claptrap. Kobolds and mitflits are both known to incorporate swarms of centipedes into cunning traps, from simple pits filled with vermin or more complex affairs involving chutes that dump the vermin onto the heads of unwary intruders.


Perception +9; darkvision, scent (imprecise) 60 feet
Skills Acrobatics +9, Stealth +9
Str +0, Dex +4, Con +2, Int -5, Wis +1, Cha -4

AC 18; Fort +7, Ref +11, Will +6
HP 30; Immunities precision, swarm mind; Weaknesses area damage 5, splash damage 5; Resistances bludgeoning 5, piercing 5, slashing 2

Speed 10 feet, fly 30 feet
Swarming Bites

Each enemy in the swarm's space takes 1d8 piercing damage (DC 20 basic Reflex save) and 1 bleed damage. The young bloodseeker swarm gains temporary Hit Points equal to the damage dealt. A creature that takes damage from the bloodseeker swarm is Drained 1 until it receives healing (of any kind or amount).

Pathfinder Society Scenario #1-02: The Mosquito WitchOGL