While not part of the mythos, Paizo has made flumphs a part of it..
This is true; the adventure is "And Madness Followed" in Dungeon #134 (May 2006). Great adventure. I never actually ran it as presented, but I used elements from it several times. One Epic-level party I ran actually had the main crafter make a pact with the King in Yellow and create the artifact book that's in the adventure.Paizo likes comic horror. One of their 3.5 Dungeon adventures even had a troupe of traveling bards putting on The King In Yellow.
While not part of the mythos, Paizo has made flumphs a part of it. Caulborn look to be something of Paizo's creation (although I could be wrong - quick googling and wikipedia searchs turned up only Paizo stuff), but have some freaky psychic stuff.
While not part of the mythos, Paizo has made flumphs a part of it. Caulborn look to be something of Paizo's creation (although I could be wrong - quick googling and wikipedia searchs turned up only Paizo stuff), but have some freaky psychic stuff.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.