The Vibur was created by Chaosium in 1995 for its Call of Cthulhu RPG.
Vibur is a 12 t tall Great Old One from another plane of existence which has been on Earth for a half-dozen millennia. Whose lumpy pear-shaped body is covered by a fur-like matted black covering. Lacking feet or limbs, it rarely moves but for convenience will shift from one point to another. Small tentacles will occasionally twitch or pass across its body. Radioactive glowing finger-length hexagonal and triangular stones are emitted like feces. Growing on its fur is a blue fungus-like substance which is dangerous to humans. The being's perception and metabolism are those of another universe, and is not fully within the material universe itself. It has incredible psionic abilities, can regenerate itself from a nuclear attack, and is able to teleport itself light years away from a nuclear strike.
Exposure to the fungus risks infection and inhalation of the spores results in infection. Which starts with random instances of extreme pain, the loss of physical senses, and experiencing confusing odors, terrible visions, and seeing colors beyond what humans normally see. Vivid nightmares, clinical insanity, and profound depression are common. Eventually the victims loses physical sensation and access to voluntary muscles, and the eyeballs are eaten away by bluish fluid. Becoming a zombie which is completely controlled by Vibur, with the victim's memory and consciousness trapped and helpless within. A third die within 2 weeks, while the majority continue to be transformed by the blue fungus as it locks the consciousness in never ending pain. By this time they are for all intents and purposes dead though the body continues to eat and digest what it consumes. It takes several more months before its tortuous undead life finally ends.