Treehouse of Horror XXI/References

Opening

 * The creature inside Professor Frink when he goes past the X-ray resembles an.
 * Frink has made his own.
 * The monster refers to , and the scene that immediately follows parodies the show's opening.
 * The first few frames of the opening credits are also done in the same style as The Office.

War and Pieces

 * The segment is a parody of .
 * Board games that come to life include:
 * Taffy Land
 * Kerplunk (various building games)
 * Drops and Risers
 * Consternation
 * Ravenous Ravenous Rhinos
 * Mouse Catch
 * Battleboat
 * Funopoly ( and Monopoly variations)
 * Crate of Apes
 * Yahtzu
 * Tiddlywonks
 * Satan's Path
 * Spinning tops
 * Connect Three
 * Tumble
 * Ice Hockey Game
 * Blocko
 * Mystery Dude (Mystery Date)
 * Colonel Ketchup.
 * Mystery Dude (Mystery Date)
 * Colonel Ketchup.
 * Colonel Ketchup.
 * Colonel Ketchup.
 * Colonel Ketchup.

Master and Cadaver

 * The title is a pun on the 2003 movie .
 * The plot parodies .
 * At the end, Maggie imitates Alex from .
 * In the beginning scene, we see that Marge was about to be attacked by a shark, referencing Jaws.

Tweenlight

 * The  series is punned in the title and parodied throughout the segment.
 * is seen with Ranger Smith's head.
 * Seen in Dracula-la Land:
 * Grandpa Munster
 * Michael Jackson
 * Blackula
 * Nosferatu
 * Booberella
 * Count von Count
 * Dracula
 * Count Fudge-ula
 * Selene

Trivia

 * This is the first time the viewers were told not to watch ever since Treehouse of Horror V.
 * This is the first time since Treehouse of Horror XVII that no-one broke the fourth wall at the end to wish the viewers happy halloween.
 * Bart, Lisa, and Milhouse were the only ones known to not be in one of the board games when they came to life, though there were some others that we didn't see (such as Maggie, Ned, or Patty).
 * This episode aired after the three week hiatus on FOX.
 * The is heard at a couple of places in the episode:
 * During the "War and Pieces" segment, when Bart and Milhouse kill enemy characters in the video game they're playing.
 * After the closing credits, when the Gracie Films card appears.
 * This is the second episode where Homer plays Drops and Rises. The first was Any Given Sundance.
 * It actually was 187 seconds between the words "Joel Cohen Will Die In 187 Seconds" and "As Predicted, Joel Cohen Just Died" in the opening credits as Joel H. Cohen is both a Co-Executive Producer and a Writer in this episode.

Goofs

 * When Edmund was about to bite Lisa they were on the window seal, but come next seen they were standing up.