Actions/Abilities/Traits: (Pathfinder 2e)
Ability
Venom Spritz
The vipers spray venom from their fangs in a defensive display. Each creature in a 10-foot cone is exposed to viper swarm venom but gains a +2 circumstance bonus to its initial saving throw against the poison.
Ability
Venomous Fangs
Each enemy in the swarm's space takes 2d8 piercing damage (DC 21 basic Reflex save) plus viper swarm venom.
Ability
Viper Swarm Venom
(poison) Saving Throw DC 21 Fortitude; Maximum Duration 6 rounds; Stage 1 1d4 poison damage (1 round); Stage 2 1d6 poison damage and clumsy 1 (1 round); Stage 3 2d4 poison damage, clumsy 2, and enfeebled 1 (1 round)
Trait
Animal
An animal is a creature with a relatively low intelligence. It typically doesn't have an Intelligence ability modifier over -4, can't speak languages, and can't be trained in Intelligence-based skills.
Trait
Swarm
A 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 grappled, prone, and restrained conditions.
Immunity
precision
swarm mind
Perception
low-light vision
scent (imprecise) 60 feet
Resistance
bludgeoning 5
piercing 5
slashing 3
Weakness
area damage 5
splash damage 5