Clacking Sea Skull Swarm
CREATURE 10Roiling about in seething waves of bleached death, clacking skull swarms arise from the remains of dozens of beheaded humanoids. The horrible clattering of the skulls' onslaught drives their prey to distraction even while they try to flee in terror.
A skull swarm is composed of reanimated masses of craniums and jawbones, forming a terrifying avalanche of undead fury. Most skull swarms are mindless, though some retain a vestige of wit, awareness, and even magical talents from life, culminating in a highly intelligent swarm mind.
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 void damage (DC 29 basic Reflex save).
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.
A creature with void healing draws health from void energy rather than vitality energy. It is damaged by vitality damage and is not healed by vitality healing effects. It does not take void damage, and it is healed by void effects that heal undead.
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.
Each enemy in the swarm's space takes 4d8 piercing damage (DC 29 basic Reflex save).