The Spirit Cave is cave known to be able to turn humans into animals. It appeared in Animals Inside.
The best explanation of the origin of the Spirit Cave comes from a myth which tells of human thieves. These theives stole treasure from the animal lords, who sought revenge by enchanting a cave in which the theives hid. Those who entered the cave would become animals, and the thieves subsequently became cowardly hyenas.
It is unknown how much of this story is true, but the Cave was successfully located by First Squad, who intended to use it to become animals so as to infiltrate East Citadel and rescue Commander ApeTrully. The cave was well-guarded, being defended by lava floes and hyenas, but the heroes proved capable of using it. The first to enter was Mystique Sonia, followed by Mighty Ray and Lin Chung, who became a swan, a boar, and a panther, respectively.
The cave was later used to allow them to return to human form.
The Spirit Cave's power can be accessed simply by entering it. At this time, its jaw-like opening will snap shut, and the spout on top of it will shoot water. The jaws will then open, revealing its occupent, now an animal.
The process can be reversed by entering the spout.
The animal that one who enters the cave will become is determined by his or her spirit animal. For example, Lin Chung's spirit animal is a panther, and he thus became a panther.
- The Spirit Cave, like the Object-Morphing Demons, is capable of transforming humans into animals. However, unlike the Demons, the Spirit Cave only transforms humans into their spirit animals.