A translucent, ethereal phantom, its form vaguely human-like but with swirling, vaporous tendrils trailing behind. Its surface shimmers with an internal, sickly greenish-white luminescence, resembling a gaseous cloud yet possessing a chilling, coherent presence. The shape is indistinct, constantly shifting, and utterly devoid of solid structure, suggesting a fleeting, intangible entity. Tactilely, it projects an intense, piercing coldness, as if the air itself has been frozen solid around it.