Rat SwarmCreature 1
Source Pathfinder Monster Core
Perception +5 (low light vision, scent (imprecise) 30 feet)
Languages none
Skills Acrobatics +8, Athletics +4, Stealth +6
Str -2, Dex +3, Con +1, Int -4, Wis +1, Cha -3
AC 14; Fort +2; Reflex +7; Will +4;
HP 14
Speed 30 feet (climb 10 feet)
Immunities precision, swarm mind
Weaknesses Area Damage 3, Splash Damage 3
Resistances Physical 6
Swarm Mind
This monster doesn't have a single mind (typically because it's a swarm of smaller creatures), and is immune to mental effects that target only a specific number of creatures. It is still subject to mental effects that affect all creatures in an area.
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 reflex save. A creature that fails its save is exposed to putrid plague.
A swarm of rats can cause total chaos within a household or business. Contracting putrid plague is all the easier when dozens of these agitated or hungry vermin gather to bite victims en masse, making rat-hunting a viable career in many parts of the world as desperate townspeople seek relief from the disease's spread.
Rats are a ubiquitous menace, scurrying through the sewers and on the streets of nearly every settlement in the world. Though a regular rat darting underfoot might startle or even frighten the average passerby, giant rats and rat swarms are far more dangerous.
Traits
Anything that doesn't list another rarity trait (uncommon, rare, or unique) automatically has the common trait. This rarity indicates that an ability, item, or spell is available to all players who meet the prerequisites for it. A creature of this rarity is generally known and can be summoned with the appropriate summon spell.
AnimalAn animal is a creature with a relatively low intelligence. It typically doesn't have an Intelligence attribute modifier over –4, can't speak languages, and can't be trained in Intelligence-based skills.
SwarmA swarm is a mass or cloud of creatures that functions as one monster. Its size entry gives the size of the entire mass, though for most swarms the individual creatures that make up that mass are Tiny. A swarm can occupy the same space as other creatures and must do so in order to use its damaging action. A swarm typically has weakness to effects that deal damage over an area (like area spells and splash weapons). Swarms are immune to the grabbed, prone, and restrained conditions.