Creeping Cone Swarm
CREATURE 10Caustic fluid seeps out from the scales of these sluglike cones, which spawn in unsuspecting hosts until they're mature enough to seek a place to root. Moving in writhing swarms that seek a habitat flush with prey, creeping cones spread Ayrzul's Blight when destroyed, but leaving them to grow unchecked poses a great risk to other creatures.
The Plane of Wood contains many unique ecosystems formed around species of wondrous trees; when Ayrzul's Blight mutates one of these trees rather than killing it, it can have a cascading effect on the tree's biome. Multiple species often mutate in tandem, becoming warped mockeries and a vector for Ayrzul's Blight. These "blight bonded" creature families are parasites and predators and typically form twisted symbiotic relationships.
Tremorsense allows a monster to feel the vibrations through a solid surface caused by movement. It is an imprecise sense with a limited range (listed in the ability). Tremorsense functions only if the monster is on the same surface as the subject, and only if the subject is moving along (or burrowing through) the surface.
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.
The creeping cones shake off a barrage of jagged, stony scales. Each creature in a 10-foot burst within 30 feet of the swarm takes 2d12+7 slashing damage (DC 29 basic Reflex save).
Each enemy in the swarm's space takes 6d6 bludgeoning damage (DC 29 basic Fortitude save). A creature that fails its save falls Prone.
30 feet.
A creature entering the aura must succeed at a DC 26 Fortitude save or become Sickened 1 until the end of its turn (Sickened 2 on a critical failure).
While within the aura, an affected creature takes a –2 circumstance penalty to recover from the sickened condition. A creature that succeeds at its save is temporarily immune for 1 minute.