"Dæmonicus" is the third episode of the ninth season of the American science fiction television series The X-Files and the show's 185th episode overall. It first premiered on the Fox network in the United States on December 2, 2001. The episode was written and directed by executive producer Frank Spotnitz. The episode is a "monster-of-the-week" episode, a stand-alone plot which is unconnected to the mythology, or overarching fictional history, of The X-Files. The episode earned a Nielsen rating of 5.5 and its premiere was viewed by 5.80 million households. The episode received mixed reviews from television critics.