Rat Swarm

Creature 1

Large
animal
swarm

Perception: +5; low light vision, scent (imprecise) 30 feet
Skills: Acrobatics +8, Athletics +4, Stealth +6; Str −2, Dex +3, Con +1, Int −4, Wis +1, Cha −3

AC: 14; Fort +2, Ref +7, Will +4
HP: 14; Immunities precision, swarm mind; Weaknesses area damage 3, splash damage 3; Resistances physical 6 (except bludgeoning)

Swarm Mind

Speed: 30 feet, climb 10 feet

Putrid Plague (disease) The Sickened and Unconscious conditions from putrid plague don't improve on their own until the disease is cured.

Saving Throw DC 14 Fortitude

Stage 1 carrier with no ill effect (1d4 hours)

Stage 2 Sickened 1 (1 day)

Stage 3 Sickened 1 and Slowed 1 (1 day)

Stage 4 Unconscious (1 day)

Stage 5 dead

Swarming Bites ◆ Each enemy in the swarm's space takes 1d6 piercing damage and must attempt a DC 17 basic Reflex save. A creature that fails its save is exposed to putrid plague.

Source: Pathfinder Monster Core

Running this fight? Add the rat swarm to the initiative tracker: type its name and the AC, hit points and Perception for initiative fill in, and the book button shows this stat block mid-fight.