The Immortal Cherufe predates human existence, emerging from the first volcanic eruptions when Earth's crust was still forming, absorbing the primordial energies that would later give rise to all cryptid species. As humans evolved and spread across continents, they encountered this ancient fire entity in different forms, incorporating it into their mythology as various fire demons and molten creatures, though its true Chilean name has endured among those who guard the oldest cryptid lore.

The Immortal Cherufe exists primarily as living magma, capable of flowing through the earth's mantle and emerging wherever volcanic activity occurs, though it can temporarily solidify into a humanoid form of obsidian and molten rock to interact with the physical world. It possesses the unique ability to absorb and incorporate traits from other cryptids it encounters, integrating their essence into its fiery core and serving as a living repository of cryptid evolution throughout Earth's history. The entity communicates through patterns formed in cooling lava and smoke signals that contain encoded knowledge about cryptid lore, though extended periods away from geothermal sources gradually diminish its power, forcing it to return to the planet's molten core to rejuvenate.

Within the cryptid ecosystem, the Immortal Cherufe functions as the elemental counterbalance to water-dwelling entities like the Kraken and Nessie, maintaining the equilibrium between fire and water that allows all cryptid species to thrive in their respective domains. Its molten core serves as the living repository of cryptid memory, preserving the oldest knowledge of each species' origins and connecting seemingly unrelated cryptids through their shared evolutionary responses to its world-shaping eruptions.