An early appearance of H.P. Lovecraft in fiction is to be found in “The Black Druid” by Frank Belknap Long, published in Weird Tales for July 1930. The Editor, Farnsworth Wright, knowingly bills the story on the contents page as: “A short tale that compresses a world of cosmic horror in its few pages”, trusting the regular reader to make the connection between “cosmic horror” and Lovecraft.
The story is interesting to scholars of Lovecraft’s life for being a knowing bit of fun-poking fictional commentary on Lovecraft, by someone who knew him on a near-everyday basis during the New York years. Lovecraft is only lightly veiled as “Stephen Benefield” and the character has similar concerns, physical attributes and locales. The story also fictionalises Lovecraft’s wife Sonia. Possibly the Bene in the name Benefield was even a comment on Lovecraft’s frugal diet, hinting at beans.
Archive.org’s OCR of the text is middling, but I’ve made the story readable as a PDF and have given it some annotations and a little introduction — along the way solving a very minor scholarly mystery about an entry in Lovecraft’s Commonplace Book.