Just read Jason Colavito's The Cult of Alien Gods: H.P. Lovecraft and Extraterrestrial Pop Culture which claims that H.P. started the whole ancient astronaut/gods from outer space craze.
I was surprised by this quote: "To be a member of a pure-blooded race ought to be the greatest achievement in life."
First of all, that's not really an achievement, now is it? But I'd always thought Lovecraft was more open-minded. Apparently he began life as a right-wing extremist but a few years after making that quote, he married Sonia Greene, a Russian Jew (big shock, they divorced a couple years later) Eventually after financial crisis after crisis, he wound up supporting Roosevelt and became a border-line socialist.
What interested me the most were his gods. I've been trying to find different groups of gods made up entirely by SF and fantasy writers but haven't been able to come up with a good source. The book listed:
Clark Ashton Smith - Tsathoggua the toad god
Robert Ervin Howard - Krom, Kathulos (independently created god very similar to Cthulhu)
Howard Phillips Lovecraft - Cthulhu and the boys
I know a few more. Fritz Leiber had an extensive pantheon of gods in the Gray Mouser series. The rabbits had a god and holy messenger in Richard Adams' Watership Down. Alan Dean Foster had many gods in his shared world universe. Robert Asprin had the gods of Thieves' World and Micheal Moorcock had them in Elric's universe.
There has got to be more. I've googled for them but I can't think of a good way to phrase it without getting all sorts of goofy crap (some of which is interesting but not what I was looking for).