The cavern beast was an unusual form of creature that was created by the Yuuzhan Vong.
The beast was an organism that was fixed in a location with its "mouth" appearing nothing more then a lichen-covered orifice. Animals and sentients were given a telepathic lure which drew in beings into its huge mouth which appeared as a cavern but was actually a type of stomach for the creature. Projected telepathic images were used to make a person appear as if they were in trouble in the minds of others bringing them into the cavern beast's home.
Once prey was inside, they were herded by parastaltic contractions and forced into specialized stomachs where they were held for storage. This was when the creature had gained enough prey then it required and were stored for digestion in the future. It was capable of providing food for captives by secreting fatty substances into stalactite formations inside the cavern which were not only edible but nutritious as well. When the cavern beast required food, it used a strange form of parastalsis to force them into the digestive chamber where they were assimilated into the body system.
There were a number of benefits prey provided the cavern beast beyond simple nutrition. The organism was capable of obtaining nutrients and elements from the wastes of its captives. Furthermore, the collective body heat of the captive beings allowed it to regulate its internal temperature.
At least one specimen of this species was known to be present on the terraformed Coruscant when it fell to the Yuuzhan Vong empire. This creature grew in the deepest part of the changing destroyed city. It lured many captives into its mouth and served as a shelter for the survivors of the city from the Yuuzhan Vong who lived inside the cavern beast. In return for shelter, they sacrificed one of their own to the creature for digestion with their policy being the latest victim of the telepathic lure being the first to be sacrificed.
Jacen Solo fell prey to the cavern beast where he saved a teenage girl that was sacrificed by the inhabitants of the cave. After saving her, the people inside the cavern beast which included the young girl turned on him and tried to sacrifice Jacen. In anger, he implanted a suggestion in the primitive mind of the cavern beast that all members of the New Republic were poisonous. The creature then vomited its prey contents and expelled them out of its orifice after which it closed its teeth preventing them from returning.
The expelled survivors were greatly angered with Jacen as they believed he destroyed their only shelter from the Yuuzhan Vong.
- The New Jedi Order: Traitor (First appearance)