The town of Dunwich, Massachusetts was thoroughly unremarkable until Wilbur Whateley was born. The family was already unpopular due to their dabbling in the occult, and when Lavinia Whateley gave birth to a strange-looking child and refused to say who the father was, it didn't improve anyone's opinion of them. Wilbur grew incredibly fast - he began talking at 11 months; by the time he was three, he looked ten years old; and at four and a half, around 15. The townsfolk didn't trust him; he gave them the creeps even more than the other Whateleys. For all that, though, they were still willing to sell cows to the Whateley mansion; money was money, after all, even if it was in weird antique gold coins. Though for some reason despite the number of livestock they bought, the herd never seemed to get bigger...The household only got more suspicious with time. The farmhouse always seemed to be mysteriously under construction, with more and more windows being boarded up; the townsfolk also suspected that interior walls were being knocked out. When Wilbur was ten, Old Whateley died, shrieking instructions to Wilbur on his deathbed; two years later, Lavinia Whateley disappeared on Halloween night and was never found.It was around this point that Wilbur began to search for an unabridged copy of the Necronomicon. He had learned all of what he knew from his grandfather's library, but his copy of that book was a shortened English version, which he apparently found insufficient. He discovers that nearby Miskatonic University has a copy, but the librarian refuses to loan it out to him. So he breaks in to steal it, only to be killed by a guard dog. And that's when things get really weird.One of H.P. Lovecraft's most famous stories, it was adapted to film twice: as a So Bad, It's GoodCult Classic in 1970, and a remake by the Sci Fi Channel in 2009. It has also been adapted thrice, generally more faithfully, as a Radio Drama, first as an episode of the long running Suspense series in the 1940s starring Ronald Colman, later by the Atlanta Radio Theater Company, and yet again by the H.P. Lovecraft Historical Society for their Dark Adventure Radio Theater series. You can read it here.
The Antichrist: Wilbur Whateley seems to be a shoo-in for the title, given the circumstances of his birth and childhood and his "goatish" appearance. As it turns out, his father is not Satan, but something far, far worse.
"Wilbur's being raised by a grandfather instead of a father, his home education from his grandfather's library, his insane mother, his stigma of ugliness (in Lovecraft's case untrue, but a self-image imposed on him by his mother), and his sense of being an outsider all echo Lovecraft himself." - Robert M. Price in the introduction to The Dunwich Cycle.
Lovecraft himself went on record saying he very much identified with Professor Armitage. Old, bookish, with occult knowledge and capable of putting two and two together in matters of horror.
Badass Grandpa: Professor Armitage, the leader of the expedition against the Horror, is 73 years old.
Beast with a Human Face: The titular horror, once revealed, is shown to be a gigantic egg-shaped tentacled multi-legged Eldritch Abomination with a distinctively yard width-long human face that resembles The Whateleys'.
Black and White Morality: Unusually for Lovecraft. Just to make it clear, the "black" isn't Yog-Sothoth, but the Whateleys, who are arguably weaponizing Yog in the form of Wilbur and his brother.
"I dun't keer what folks think—ef Lavinny's boy looked like his pa, he wouldn't look like nothin' ye expeck. Ye needn't think the only folks is the folks hereabouts. Lavinny's read some, an' has seed some things the most o' ye only tell abaout. I calc'late her man is as good a husban' as ye kin find this side of Aylesbury; an' ef ye knowed as much abaout the hills as I dew, ye wouldn't ast no better church weddin' nor her'n."
Prophecy Twist: Early in the story, Old Whateley says that one day, they'll hear a child of Lavinia's screaming his father's name from Sentinel Hill. Turns out it's Wilbur's twin.
Psychopathic Manchild: Wilbur can easily be seen as this. He doesn't seem to have noticed, or maybe just doesn't care that most people really don't want the Earth to be pulled into horrible alien dimensions of lunacy and shit like that. Also a manchild in a more literal sense, as he is physically a fully bearded adult in his early teens.
"Inbreeding? . . . God, what simpletons! Show them Arthur Machen's Great God Pan and they'll think it a common Dunwich scandal! But what thing - what cursed shapeless influence on or off this three-dimensional earth - was Wilbur Whateley's father?"
Armitage's brief monologue that closes the story also recalls some of the speeches by Dr. Raymond in Great God Pan.
Another Machen example: Wilbur's diary, as decoded by Armitage, is clearly inspired by "The White People," which purports to be the diary of a young girl's initiation into pagan witchcraft. The terms "Aklo" and "Voorish" also come from there.