Vitalia
CREATURE 18Foul occult magic, rare alchemical reagents, and copious amounts of spilled blood are the keys to creating a vitalia-also known as a heart horror-though thankfully the exact means of their creation has been long forgotten.
Now, most vitalias now come into being by sheer accident. This unusual life-form cannot live without regular contact with blood, much like how fish cannot live long outside of water. Because of this, vitalias are rarely found outside the lairs of mad alchemists or wizards, living in pools of the life-giving substance. Physically, a vitalia somewhat resembles a blood-red giant jellyfish, though it also bears some semblance to a giant human heart.
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.
The vitalia can detect any creatures that have a heartbeat.
A monster with this ability regains the given number of Hit Points each round at the beginning of its turn.
4d8+10 bludgeoning damage, DC 37 basic Fortitude
The monster deals the listed amount of damage to any number of creatures Grabbed or Restrained by it. Each of those creatures can attempt a basic Fortitude save with the listed DC.
All creatures in the area are Concealed from one another. A creature that benefits from consuming blood (such as bloodseekers or vampires) gains fast healing 10 while in the area. While in the area, a creature taking persistent bleed damage cannot end that condition, even if it spends actions to attempt a flat check to do so.
The rain lasts for 1 minute.
Effect: Sanguine Rain
The monster can instead use Grab and choose one creature it's grabbing or restraining with an appendage that has Grab to automatically extend that condition to the end of the monster's next turn.