Those Who Serve the Laughing Madness
Description: Remarkably civilized cult worshiping a cosmic horror whose mere sight drives men mad.
On paper, this cult should be prettily straightforwardly awful. Those Who Serve the Laughing Madness are devotees of, well, the Laughing Madness, which is a fairly standard Elder God from another reality whose presence sends mere mortals down the spiral of madness, etc etc, and he will surely come at the End Times, yadda yadda, there is no defense against his majestic insanity, blah blah blah. All of that previous sentence was literally taken from a fairly famous sermon done by a high priest of the cult itself, complete with various mildly obscene hand gestures at appropriate points to indicate particularly self-indulgent passages.