The Black Crochan, commonly known as The Black Cauldron, is a legendary, magical iron cauldron-like artifact that both reanimates the dead as deathless and mindless slaves and creates the Cauldron Born, and it plays a major role in the Chronicles of Prydain book series including the titular second book The Black Cauldron and the eponymous 1985 Disney film The Black Cauldron.
Chronicles of Prydain
The origin of the Black Crochan is unknown, though it was owned for a long time by the enchantresses, Orddu, Orwen and Orgoch. Arawn made a deal with the three to obtain the Cauldron and used it to create his own army of Cauldron-Born; however, he kept it beyond the agreed-upon time and the mysterious women eventually stole it back, taking it to their home in the Marshes of Morva.
In their quest to destroy the Cauldron, Taran and his companions traded the powerful brooch of Adaon to the enchantresses; however, they then found its power could only be broken if a living human willingly threw himself into the Cauldron, a fatal act. After the Cauldron's seizure by King Morgant, this was finally done by Prince Ellidyr.
The Black Cauldron
Its exact origins are unknown, though legends says the gods imprisons the soul of a malicious king into the molten iron of what is to be forever known as the Black Cauldron, for untold centuries it remains hidden while many people with lust for power searches for it. The only one among those is none other then the deathly and malevolent emperor, the Horned King.
The Horned King finally have it in his grasp while his mortal soldiers captured Taran and 2 of his 3 friends but Gurgi alone escaped, and return them to the castle. The Horned King uses the cauldron to raise the dead and his Cauldron-Born army begins to pour out into the world of Prydain.
Gurgi manages to free the captives and Taran resolves to cast himself into the cauldron, but Gurgi stops that and advances himself instead. The undead army collapses. When the Horned King spots Taran at large, he infers the turn of events and throws the youth toward the cauldron, but the magic is out of control. It consumes the Horned King and destroys the castle, using up all its powers.
The 3 witches come to recover the now inert Black Cauldron. Taran has finally realized Gurgi's true friendship, however, and he persuades them to revive the wild thing in exchange for the cauldron, giving up his magical sword permanently. Fflewddur goads the reluctant witches to go ahead and demonstrate their powers by the revival, which they do. Taran, Ellonwy and Fflewddur Fflam were reunited with Gurgi at last.
Appearances in other media
The Black Cauldron also appeared as a key item in the 1986 videogame adaption of the Disney movie of the same name.