Actions/Abilities/Traits: (Pathfinder 2e)
Ability
Boneshard Burst
When a clacking skull swarm is reduced to 0 Hit Points, it erupts in an explosion of foul energy and bone fragments in a 30-foot burst, dealing 2d12 piercing damage and 2d12 negative damage (DC 29 basic Reflex save).
Ability
Chattering Teeth
(arcane, auditory, aura, emotion, enchantment, incapacitation, mental) 60 feet. A clacking skull swarm emits a cacophony of chattering. A creature entering or beginning its turn within the area must succeed at a DC 29 Will save or become confused for 1 round. A creature that successfully saves is immune to that swarm's chattering teeth for 24 hours. The swarm can stop or resume this ability as a free action.
Ability
Shrieking Scream
(auditory, emotion, enchantment, fear, mental) The clacking skull swarm emits a terrifying, painful scream that deals 10d6 sonic damage to all creatures in a 30-foot cone (DC 29 basic Will save). A creature that fails this save is also frightened 1 (frightened 2 on a critical failure). The swarm can't use Frightening Scream again for 1d4 rounds.
Ability
Swarming Gnaw
Each enemy in the swarm's space takes 4d8 piercing damage (DC 29 basic Reflex save).
Trait
Mindless
A mindless creature has either programmed or rudimentary mental attributes. Most, if not all, of their mental ability modifiers are -5. They are immune to all mental effects.
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.
Trait
Undead
Once living, these creatures were infused after death with negative energy and soul-corrupting evil magic. When reduced to 0 Hit Points, an undead creature is destroyed. Undead creatures are damaged by positive energy, are healed by negative energy, and don't benefit from healing effects.
Immunity
death effects
disease
mental
paralyzed
poison
precision
unconscious
Perception
darkvision
Resistance
bludgeoning 5
cold 10
electricity 10
fire 10
piercing 10
slashing 10
Weakness
area damage 10
splash damage 10