Juiblex

Jubilex (alternate spellings: Juiblex, Juibilex; also called The Faceless Lord) is a fictional character, a demon lord sometimes connected to Abhoth from H. P. Lovecraft's Cthulhu Mythos. He does not have a physical form as we know it; those who have visited his dark, muddy realm claim he is a slime-like creature who swallows other creatures alive, spits acidic secretions and causes diseases in his victims which can be almost instantly fatal.

Jubilex also appears as an enemy in the roguelike computer game Nethack (spelled Juiblex).