mephitic

pahanhajuinen foul-smelling or noxious, particularly of a gas or atmosphere.
(quote-book)|title=(w)|chapter=V|passage=It is impossible to convey, in words, any idea of the hideous phantasmagoria of shifting limbs and faces which moved through the evil-smelling twilight of this terrible prison-house. Callot might have drawn it, Dante might have suggested it, but a minute attempt to describe its horrors would but disgust. There are depths in humanity which one cannot explore, as there are mephitic caverns into which one dare not penetrate.
(quote-book)