The first Disney movie to have full closing credits with music, and the first to have any sort of closing credits since Alice in Wonderland (1951) (which only featured a Voice Cast, despite it already appearing in the Opening Credits (only featuring the voice actor names without the ones they voice)).
According to animation artist Michael Peraza Jr., when Disney started having screenings for the public at the studio theater to gather their reactions to the rough cut of this film, he knew that the "un-dead" section would most likely be revolting to some in the audience who would not expect to see a bunch of rotted corpses slowly fermenting. When the film reached the "un-dead" sections close to the end of the film, the doors opened and a mother was angrily leaving with her two wailing children. She was followed by another, and soon there was a sizable exodus of crying kids and upset parents fleeing from the theater. The un-dead sections were quickly cut from the film.
The management team at Disney changed during production. New studio chairman Jeffrey Katzenberg screened the mostly-completed film and was appalled by its darkness. He suggested editing the film, and when producer Joe Hale protested (animated films are typically not edited in post production the same way live-action films are), Katzenberg himself brought the film into an editing bay and began cutting it himself, ultimately extracting twelve minutes from the final run time.
The production of this film can be traced back to 1971, when the Disney Studio purchased the screen rights to Lloyd Alexander's "The Chronicles of Prydain". The film took over 12 years to make, 5 years of actual production, and cost over $25 million. Over 1,165 different hues and colors were used, and 34 miles of film stock was utilized.
This was the first animated Disney movie to be filmed in widescreen since Sleeping Beauty (1959). Movies released in between involved matting of the top and bottom of the filmed image in order to make a widescreen image suitable for the movie theaters.
Tim Burton, who worked as a conceptual artist on this film, wanted to incorporate minions of the Horned King that were akin to the "facehuggers" from the Alien (1979) movie series. Some samples of his work can be seen on Disney's 2000 DVD of this title.
There is an urban legend that, despite the film's failure in the US, it was popular in Japan, so much so that the creator of the Legend of Zelda series, Shigeru Miyamoto, based a lot of the game's elements on this film.
According to producer Joe Hale, "When [Jeffrey] Katzenberg first screened the film he told us to cut it by 10 minutes. Roy [Disney] and I got together and found some scenes we could get rid of that didn't affect the story that much." When they ran it again for Jeffrey Katzenberg and the film finished he asked Roy Edward Disney, "Is that 10 minutes?" When Disney replied that no it was only around 6 minutes. Katzenberg stated, "I said 10 minutes!" Hale continued, "Eventually he cut out about 12 minutes, which really hurt the picture."
The movie is loosely based upon the first two books in Lloyd Alexander's Prydain Chronicles ("The Book of Three" and "The Black Cauldron"). The Chronicles, in turn, are loosely based on the mythology of ancient Wales, a collection of tales known as the Mabinogion.
During the beginning of the film when Dallben uses Hen Wen's magic to find the Horned King, the first image that appears in the water was a recycled section from "The Night On Bald Mountain" sequence from Fantasia (1940).
This was the first (and last) movie since The Jungle Book (1967) where the old multi-plane cameras were brought briefly out of retirement (with a few improvements this time). New technologies such as computer-generated imagery now available to all studios have made multi-plane photography obsolete.
According to former Disney animator Michael Peraza Jr., there were multiple openings that were conceptualized by different people. Peraza worked with art director Don Griffith and artist Vance Gerry on one version that showed the Horned King and his gang burning down a village. Sweeping flames were used as transitions between scenes of destruction. Mike Peraza and the artists wanted a contrast to the peace and quiet of Taran's farm life.
A technological breakthrough in this movie was the development of the APT (Animation Photo Transfer) process. The first major change in the Studio's method of transferring the artist's drawings to a cel since Xerox copying replaced hand-inking over 20 years earlier, the APT greatly improved the quality of the animator's art. Dave Spencer was awarded an Oscar for his development of the APT process.
This is the first Walt Disney film to feature the "classic" Walt Disney Pictures logo: the white castle and text over a blue field. This logo would be used until the new CGI logo was introduced with Pirates of the Caribbean: Dead Man's Chest (2006).
Kellogg released plastic models of 8 of the characters free with their Cornflakes cereal. They include one of the witches who they referred to as Orddu, but the model is actually of her sister witch, Orwen.
According to animation artist Michael Peraza Jr., Disney showed this film to the public at the studio theater to gather their reactions to the rough cut of this film. But the reactions of the audience were mostly negative due to the dark content of the film. So some scenes were cut from this film.
Video cameras gave animators and directors an immediate and inexpensive record of what their efforts might look like. The dimensions and volume of the objects were fed into a computer and then their shapes were perfectly maintained as their movement was generated by programming.
A video game of the same name was designed by Al Lowe of Sierra On-Line and released in 1986. It was made shortly after the first King's Quest game, so it resembled that adventure in many ways. Along with The Dark Crystal it remains one of only a few adventure games by Sierra to be based on films.
The version of the film released to theaters omits about 10 to 15 minutes fully animated footage, including: Scenes of graphic violence as Taran fights his way out of the castle, and shots of Eilonwy wearing ripped garments as she's hanging for her life with Taran and Fflewddur. The most well-known deleted scene, due to a clumsy jump it left in the film's soundtrack and a cell of the infamous scene appearing online, is that of a man being mauled by one of the Cauldron born. Other deleted scenes: Some Fairie footage and a Fairie musical number, scenes of the Horned King with a flowing cloak, a fight scene between Taran and the Horned King before he is sucked into the cauldron.