H.P. Lovecraft/YMMV


 * Accidental Aesop - Considering H.P Lovecraft's general xenophobia and racism, it's likely he intended the final revelation in Facts Concerning the Late Arthur Jermyn and His Family- that one of the title character's great-great-great grandparents was some sort of pre-human 'ape-goddess'- to be legitimately horrifying enough to justify his fatal Heroic BSOD. Ninety-odd years later, when what amounts to almost literally the exact same revelation about a huge swath of the current population is met with a profound 'meh' outside of the scientific community, the really disturbing thing about the story seems more to be how truly fragile poor Arthur's sense of proportion and grip on reality are.
 * Brain Bleach - Do NOT look up any pictures of the Great Old Ones or the Outer Gods on Deviantart, whatEVER you do.
 * Family-Unfriendly Aesop - "The universe is a fundamentally indifferent and horrifying place, full of Eldritch Abominations, Starfish Aliens, minorities and seafood, and ignorance of its true nature is the only thing keeping us from madness."
 * Due to Values Dissonance, this can also come off as somewhere between "Humanity is fatally narrow-minded" and No Transhumanism Allowed, with descriptions of the Deep One civilization or humanity once the stars come right again looking more like societies of transcendent One Winged Angels than sub-human horrors, and the horrified narrators seeming to prefer species-wide stagnation or death over adaptation to the larger universe.
 * Nightmare Fuel - Like saying that grass is green.
 * Seinfeld Is Unfunny (Thanks to his influence, many of Lovecraft's themes have become horror clichés.)
 * Squick (Read a detailed biography of the man... and shiver.)
 * Tear Jerker - The Reveal of "The Outsider".
 * Values Dissonance: Lovecraft was very racist and this causes some of his stories to have uncomfortable racial tones.
 * "Medusa's Coils" is the most notoriously racist of all Lovecraft's works, and treats the revelation of a generations-ago Anglo-Saxon/African marriage to be something as utterly horrific as the various alien ghoulies that tend to show up in Lovecraftian horror. Many readers in the modern era tend to find the final statement (copied below) to be Nightmare Retardant.
 * It would be too hideous if they knew that the one-time heiress of Riverside -- the accursed gorgon or lamia whose hateful crinkly coil of serpent-hair must even now be brooding and twining vampirically around an artist's skeleton in a lime-packed grave beneath a charred foundation -- was faintly, subtly, yet to the eyes of genius unmistakably the scion of Zimbabwe's most primal grovellers. No wonder she owned a link with that old witch-woman -- for, though in deceitfully slight proportion, Marceline was a negress.


 * Wangst - His lengthy Purple Prose along with his crapsack worldview can come across as a badly done attempt to give a Despair Speech.