There was thunder in the air on the October night that I first heard nonnies speak of the tainted legacy of Howard Philips Lovecraft, a man driven to the edge of insanity by the horrors that lurked around him, tortured by the hideous truth that beat beneath his pale sweaty skin, faint, subtle, but unmistakable to the eyes of genius. No wonder he spoke of unknowable horrors, Old Ones and eldritch contradictions of all matter, force and cosmic order– for, though in deceitfully small proportion, Lovecraft was a Welshman.
It's basically that Lovecraft was terrified of brown people so he made them the scary monsters in his work, and when he discovered he was part Welsh he totally couldn't deal with it and wrote a story in which a guy discovers that his grandmother was an ape from deepest, darkest Africa, and kills himself, or something. This sparked a huge wank in which mostly everyone was just bemused, and nonnies thought it was funny because it sounds so ridiculous to modern ears to have such a freak out over something we would no longer bat an eyelid at, although there's actually coincidentally a discussion linked in this post which explains why the idea of brown people and part Welsh might have been linked in his mind and horrified him so much, which isn't so funny.
Nonnies noticed how much Cthulhu language resembles Welsh and it became a running joke that you could scare Lovecraft by mentioning ~broooooown peooople~ and the Welsh are clearly eldritch and strange and can't be trusted because they are part aquatic and hiding their tentacles, and the most frightening thing that could happen to someone is discovering they are… part Welsh, and that when someone seems a bit otherworldly and off it must be because they are *gasp*… part Welsh” (source)
FFA Dreamwidth Post #84 was named "I get to be an eldrich horror!" at the bequest of those mocking imps from Tartarus who wrapped their writhing feelers about poor Lovecraft's shoulders.
(Illustration by Sean Phillips; source.)