Mad Monster Party? (U.S. movie)

In order to keep costs of the film’s budget at a minimum, the film's producers chose to alter most of the characters’ names as they didn’t want to pay royalty fees for using the names of various copyrighted characters. That is why many of the characters are all referred to by different names; i.e., King Kong is referred to as "IT", the Frankenstein’s Monster is refferred to as "Fang", the Bride of Frankenstein is simply "the Monster's Mate", Quasimodo is called "the Hunchback of Notre Dame" and the Creature from the Black Lagoon is called simply "the Creature". While the names "Count Dracula", "Dr. Jekyll and Mr. Hyde", and "the Invisible Man" were within the public domain at the time of the film's production and which thus means that no royalty fees were required for their use, so their names remained unaltered for the film.

With the exception of Baron Boris von Frankenstein, Allen Swift voiced every other male character that appears in this film. Despite this film being a musical and Allen Swift voicing a majority of the characters, none of his characters actually sing throughout the duration of the film.

The Werewolf’s Gypsy clothing in the film is a reference to the "The Wolf Man" (1941), in which the werewolf who bit Larry Talbot (Lon Chaney Jr.) was a Gypsy named Bela (played by Bela Lugosi).

The name of Baron Boris von Frankenstein's Caribbean island home in the film is a pun as "Isle of Evil" sounds like the phrase "I love evil".

The stop motion puppet heads of the "Boris" and "Monster" figures in the film are the same basic shape, appropriately enough, with Boris' face being fine-tuned for a more human appearance and the Monster's face having a more monstrous look, the similarities are very noticeable when the figures' heads are in the same scene, both more or less in profile, during the "greeting of the guests" scene.

With his immense vocal talents, Allen Swift was successfully able to provide a variety of voice impersonations to the majority of the characters he voiced. His Felix Flanken voice was based off of actor Jimmy Stewart; his Yetch voice was based off of actor Peter Lorre(hence Yetch was designed to resemble Lorre); his Invisible Man voice was based off of actor Sidney Greenstreet; his Dracula voice was appropriately based off of actor Bela Lugosi, and his Sea Captain voice was based off of actor Charles Laughton.

Kronkite (the last name of the pharmacist in the film who Felix Flanken works for) is ironically the German word for "sickness".

Harvey Kurtzman, one of the writers for the film, has often used what is called "chicken fat humor" in his work for MAD magazine, which is also known simply as Jewish comedy. Such examples include a scene of Yetch being flicked by "It" (the giant ape) and is yelling out "Oy vey!" as he sails through the air. Also, the name "Felix Flanken" itself is a Jewish reference to a particular cut of meat called "Flanken" used in a Jewish dish of the same name.

Goof: in one scene when the clock was chiming, Baron Boris von Frankenstein announces that it is 1:00, however the clock actually reads as 6:55. It was even chiming at six times to prove that it is not 1:00.

Baron Boris von Frankenstein’s name is based on both Boris Karloff’s name and the name of Dr. Frankenstein’s son Baron Wolf von Frankenstein from Universal’s third Frankenstein film "Son of Frankenstein".

This film was Boris Karloff’s final acting role in a Frankenstein related film.

In one scene, Dracula announced to everyone with "And now, friends, you'll see who was the original Batman". Phyllis Diller who voiced the Monster’s Mate had previously guest starred in an uncredited role in an episode of the 1966 Batman TV series. She portrayed the Scrubwoman in season two episode five titled "The Minstrel's Shakedown".

When the film was released on DVD release by Anchor Bay Entertainment, at the very end of the film, the word "Yeah", which was sung by Francesca and was followed by a couple of creepy musical notes, was completely omitted for reasons unknown.

In recent home video releases of the film, a few seconds of footage had been cut for reasons unknown. The scene in question was at the pharmacy when the postman shows Felix Flanken a fancy stamp on his letter, the scene of Felix looking over the letter for the stamp and the postman pointing to it was cut. So, right after the postman refers to the stamp as "fancy", it then shifts to a close-up of the Baron Boris von Frankenstein stamp on the corner of the envelope.

Although the film was constructed in Academy ratio (1.33:1), the film was intended to be screened in a 1.85:1 widescreen aspect ratio. This aspect ratio was previously never been released on television or any home video format. The only way that the film can be viewed in a widescreen ratio on a 16x9 television is by using the zoom one setting. For many years, it was believed that the original ratio aspect of the film was lost. However it wasn’t until May 24, 2023, when a new Blu-ray of the film was released which featured a new 2023 color-corrected master in the correct aspect ratio of 1.85:1, while the full frame 1.33:1 from the older home video releases is viewable as an alternative on the same Blu-ray release. Making the film’s original aspect ratio viewable for the first time since its original theatrical release.

The final scene in the film with Felix and Francesca sitting on the boat spoofs the famous final scene in the 1959 comedy "Some Like It Hot" in which Felix’s line towards Francesca "Well, Francesca, none of us are perfect." Is similar to Joe E. Brown as Osgood Fielding III’s line towards Jack Lemmon as Jerry, "Well, nobody's perfect."

This was the third theatrically released Rankin Bass Production animated film.

It was originally rumored that that Forrest J. Ackerman was an uncredited writer to the film’s screenplay. This was eventually proven to be false.

Upon the completion of the screenplay, the only additional scenes that were added was the Chef Mafia Machiavelli scene and the scene of Boris, Yetch and the zombie bellhops preparing to take off flying in their airplanes.

Despite that this film was a musical, it’s soundtrack wasn’t released on any music formats until 31 years after its theatrical release.

According to Frankenstein’s letter to Felix, the Kronkite Pharmacy is located on 100 Back Way; Book Bay, Vermont; USA. This address is actually fictional, as no actual street or town by those names existed within the state of Vermont.

Arthur Rankin cited Francesca as his favorite character from this movie.

The design of Count von Count from Sesame Street consisting of a monocle and pointed nose was inspired by this movie's version of Dracula.