A society of individuals who know the truth about the existence of unicorns, as historical (and magical) animals who lived for generations, along with the dinosaurs, but were wiped out by evil wizards during the Dark Ages. You become initiated by drinking Guinness from the horn of the last unicorn.
Chris: I'm a member of the Unicornites.
Luke: What does that mean?
Chris: I know the truth about the magical, wondrous creature known as the unicorn