Born from the darkest depths of Scottish folklore, the Formless Nuckelavee evolved beyond its original half-horse, half-human form to become a cosmic entity capable of flowing between cryptid manifestations across all cultures. After centuries of absorbing the essence of cryptids it encountered, it transcended physical limitations, becoming a primordial force that simultaneously exists within all cryptid legends while remaining distinctly itself.

The Formless Nuckelavee exists in a perpetual state of horrific transformation, able to manifest characteristics of any cryptid while maintaining its core essence of dread and ancient malice. It leaves traces of brackish seawater wherever it manifests, marking the boundaries between worlds with a distinctive sulfurous scent. Though primarily composed of a viscous, skin-like substance that constantly shifts and reforms, it can solidify into terrifying approximations of regional cryptids when necessary to interact with the physical world.

The Formless Nuckelavee serves as both witness and catalyst to cryptid manifestations worldwide, its presence intensifying the supernatural qualities of local cryptids while creating subtle connections between seemingly isolated phenomena. It maintains the cosmic balance between the hidden and revealed aspects of cryptozoology, determining which cryptids remain legendary and which occasionally breach the veil of human perception.