Rat Snake SwarmCreature 2
Source Pathfinder Monster Core 2
Perception +8 (low light vision, scent (imprecise) 30 feet)
Languages none
Skills Acrobatics +10, Stealth +8
Str +0, Dex +4, Con +2, Int -4, Wis +2, Cha -3
AC 16; Fort +8; Reflex +10; Will +6;
HP 25
Speed 20 feet (climb 20 feet, swim 20 feet)
Immunities precision, swarm mind
Weaknesses Area Damage 3, Splash Damage 3
Resistances Bludgeoning 3, Piercing 5, Slashing 5
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.
Mass Wriggle
Trigger The rat snake swarm takes damage from a melee Strike
Effect Snakes slither up and around the creature's weapon and limbs. The target must succeed at a DC 15 will save or become Frightened 1.
Swarming Strikes
Each enemy in the swarm's space takes 1d8 piercing damage (DC 17 reflex save).
A solitary snake might be no cause for alarm, but a hissing mass of frenzied snakes can make even seasoned adventurers shudder. Rat snakes can reach lengths of up to 10 feet, and they gather en masse to hibernate as well as to breed. Though nonvenomous, these territorial snakes will strike anything that threatens them.
Snakes of some variety thrive in every non-arctic ecosystem, each with their own particular hunting patterns and defense mechanisms.
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.