Edgar Allan Poe is often mentioned in discussions of the grotesque, in particular his short story The Masque of the Red Death (1842). The full text is available here, and I would definitely recommend reading it. So short, yet so incredibly suspenseful and evocative.
Although Poe's work is of great interest in general, this tale is a special favourite because he actually uses the word 'grotesque.'
The story begins with an horrific disease; the Red Death.
"The red death had long devastated the country. No pestilence had ever been so fatal, or so hideous. Blood was its Avatar and its seal -- the madness and the horror of blood. There were sharp pains, and sudden dizziness, and then profuse bleeding at the pores, with dissolution. The scarlet stains upon the body and especially upon the face of the victim, were the pest ban which shut him out from the aid and from the sympathy of his fellow-men."
Bloodsplosion. This would be a classic zombie apocalypse if the infected didn't die so very quickly.
The smug Prince Prospero ("happy and dauntless and sagacious") takes a thousand of his closest non-dead or bloody friends and locks himself away in a reinforced Abbey to wait out the ordeal. After about six months, and probably slightly bored, he organises a masquerade. Everyone gets dressed up and makes a spectacle of themselves, all the more horrible if you imagine the gory devastation happening outside.
This is how Poe describes the revelers:
"Be sure they were grotesque. There were much glare and glitter and piquancy and phantasm -- much of what has been seen in "Hernani." There were arabesque figures with unsuited limbs and appointments. There were delirious fancies such as the madman fashions. There were much of the beautiful, much of the wanton, much of the bizarre, something of the terrible, and not a little of that which might have excited disgust."
In the middle of all the dancing, a mysterious figure appears.
"And the rumor of this new presence having spread itself whisperingly around, there arose at length from the whole company a buzz, or murmur, of horror, and of disgust."
Who is this out-grotesqueing the grotesques?
"The figure was tall and gaunt, and shrouded from head to foot in the habiliments of the grave. The mask which concealed the visage was made so nearly to resemble the countenance of a stiffened corpse that the closest scrutiny must have difficulty in detecting the cheat. And yet all this might have been endured, if not approved, by the mad revellers around. But the mummer had gone so far as to assume the type of the Red Death. His vesture was dabbled in blood -- and his broad brow, with all the features of his face, was besprinkled with the scarlet horror."
Uh-oh. What happens next? You will have to read the story for yourself.
There have been a few film adaptations, of course, although this Roger Corman effort doesn't seem to have much to do with the original story.
I don't recall any Devil worshiping.
A band called Stormwitch composed a song in honour of The Masque of the Red Death. In fact, they dedicated a whole album (Tales of Terror) to Poe in 1985. Rock on.
Just in case all this blood stuff makes you uncomfortable, check out this "Little Gothic Library" print by Aussie artist Martin Harris:
He also did one for another of my favourites: The Fall of the House of Usher.
Charming. And menacing. But mostly charming.