Set in the mythical land of Prydain during the Early Middle Ages, the film centers on a wicked emperor known as the Horned King, who hopes to secure an ancient magical cauldron that will aid him in his desire to conquer the world.

The newly appointed Walt Disney Studios chairman Jeffrey Katzenberg ordered the scenes to be cut, which caused its release to be delayed to 1985.

Dallben learns that the evil Horned King is searching for a mystical relic known as the Black Cauldron, which can create an invincible army of undead warriors known as the Cauldron-Born.

Eidilleg's obnoxious right-hand man Doli is assigned to lead the friends to the Marshes of Morva while the Fair Folk escort Hen Wen back to Dallben.

Taran has realized Gurgi's true friendship, and asks them to revive his friend in exchange for the cauldron, choosing to give up his sword.

[12] Because of the numerous storylines, and with over thirty characters in the original series, several story artists and animators worked on the film's development throughout the 1970s.

Veteran artist Mel Shaw created preliminary conceptual pastel sketches, which future Disney president and CEO Ron Miller considered to be too advanced for the newly-hired animators.

"[18] When production on The Fox and the Hound (1981) had wrapped, several feature animation directors Art Stevens, Richard Rich, Ted Berman, and Dave Michener became involved in The Black Cauldron.

[21] Musker and Ron Clements, also citing creative differences, were removed from the project and began development on The Great Mouse Detective (1986).

[13] Taran and Eilonwy eventually acquired elements of the past designs and costumes of earlier Disney characters, especially the latter, who was drawn to resemble Princess Aurora.

[27] That same year, Mills hosted an episode of NBC's Disney's Wonderful World, in which she met with Hale and the directors to discuss the part.

Shortly before the film's initially planned 1984 theatrical release, a test screening for the rough cut of The Black Cauldron was held at the studio's private theater in Burbank, California.

First, the rough animation would be photographed onto high-contrast lithographic film, and the resulting negative would be copied onto the plastic cel sheets that would transfer lines and the colors which eventually eliminated the hand-inking process.

[35][36] However, as the APT-transferred line art would fade off of the cels over time, most of the film's animation was done using the xerographic process, which had been used by Disney since the late 1950s.

[38] Though The Black Cauldron was released a year before The Great Mouse Detective, both films were in production simultaneously for some time and the computer graphics for the latter were done first.

For other effects, animator Don Paul used live action footage of dry ice mists to create the steam and smoke coming out of the cauldron.

The score which is composed and conducted by Elmer Bernstein; he used the ondes Martenot to build upon the dark mood of Prydain, an instrument he used in Trading Places (1983) and Ghostbusters (1984).

[41] The album soon fell out of print and many of the film's tracks did not resurface until a bootleg copy entitled "Taran" was supplied to soundtrack specialty outlets in 1986.

[7] The film was not only outgrossed by The Care Bears Movie, an animated feature with a significantly lower budget, but also by a rerelease of the studios' own One Hundred and One Dalmatians.

The critics' consensus reads: "Ambitious but flawed, The Black Cauldron is technically brilliant as usual, but lacks the compelling characters of other Disney animated classics.

He noted how "involving" the story was, and felt "the key to the movie is in the richness of the characterizations, and the two best characters, I think, are the Horned King and a fuzzy little creature named Gurgi.

"[53] Charles Solomon of the Los Angeles Times wrote that the "highly dimensional sound track, with its opulent Elmer Bernstein score and excellent vocal performances, is a technological work of art.

He felt that if "its script and direction were equal to the animation, Cauldron would be a masterpiece to rank with Snow White and Pinocchio, instead of the frustrating, beautiful, exciting and ultimately unsatisfying film that it is.

"[55] London's Time Out magazine deemed it "a major disappointment", adding that "the charm, characterization and sheer good humor" found in previous Disney efforts "are sadly absent".

[56] Charles Champlin, also from the Los Angeles Times, wrote that The Black Cauldron lacks "the simplicity and the clarity of great fairy tales, or the child-sized wonder of Margery Sharp's stories that became The Rescuers, the last really successful Disney animated feature.

"[57] Jeffrey Katzenberg, then-chairman of the Walt Disney Studios, was dismayed by the product and the animators believed that it lacked "the humor, pathos, and the fantasy which had been so strong in Lloyd Alexander's work.

[14] The film received a DVD release with a 2.20:1 non-anamorphic widescreen transfer in 2000, as part of the Walt Disney Gold Classic Collection line, featuring an art gallery, a new game The Quest for the Black Cauldron, and the 1952 Donald Duck short Trick or Treat.

It contained the original 2.35:1 anamorphic widescreen transfer, the new Witch's Challenge game, an unfinished deleted scene, and all of the features from the 2000 DVD release.

[64][65] On July 11, 1986, Tokyo Disneyland opened Cinderella Castle Mystery Tour, a walk-through attraction in which the Horned King makes an appearance.

During the battle against Maleficent's forces by Goofy, Donald, Phillip, and Aurora, a cameo appearance is made by Creeper with other Disney villains.