The Black Cauldron was a squat, black pot, half as tall as a man.
"Its ugly mouth gaped wide enough to hold a human body. The rim of the cauldron was crooked and battered, its sides dented and scarred; on its lips and on the curve of its belly lay dark brown flecks and stains, which Taran knew were not rust. A long, thick handle was braced by a heavy bar; two heavy rings, like the links of a great chain were set in either side. Though of iron, the cauldron seemed alive, grim and brooding with ancient evil. The empty mouth caught the chill breeze and a hushed muttering rose from the cauldron's depths, like the lost voices of the tormented dead." -- The Black Cauldron, Chapter 13: "The Plan".
Powers and OriginsCauldron-Born were "the dead whose bodies Arawn steals from their resting places in the long barrows" and "steeps them in a cauldron to give them life again". These Cauldron warriors were invulnerable to all mundane weapons. A sword buried in their breast would briefly halt the deathless soldier's advance; all wounds were bloodless and had no effect on the Cauldron-Born. The warriors were mute, emanating a "ghostly silence", and evidently felt no pain. In the act of their unnatural resurrection, Arawn destroyed all memory of their former selves; the undying men could only fulfill their master's commands, and to bring others into death's cold bondage.
The Cauldron's precise origins are unknown. According to the enchantresses Orddu, Orwen, and Orgoch, it was they who had owned the pot and struck a bargain with Arawn, who went on to use the Crochan to create his deathless army. However, the Death-Lord kept it beyond the agreed-upon time, and the witches stole it back, absconding with the Cauldron to their cottage in the Marshes of Morva. We are never given to know if the vessel was created by the three witches, or if perhaps it was a product of the Fair Folk's craft. Any similar guess seems equally likely, while the mystery of the Crochan's making remains unanswered.
AppearancesPrince Gwydion convened a council at Caer Dallben and declared his intentions to destory the Cauldron. It seemed that men were disappearing, while more Cauldron-Born had swelled Arawn's ranks. Yet the strategic plan to seize the Cauldron met a snag when it turned up missing! During the quest to find it, Taran and his Companions traded the powerful Brooch of Adaon to the enchantresses; only then did the group learn that the Cauldron's power could only be broken if a living human willingly threw himself into its mouth, a fatal act. After King Morgant absconded with the pot, this final sacrifice was finally achieved by Prince Ellidyr. When he forced himself into the Cauldron it shattered around his corpse.
The Cauldron-Born were neither destroyed nor weakened by the Cauldron's destruction. Arawn used the deathless warriors to assault Caer Dathyl and raze the mighty fortress of the Sons of Don to the ground. Later Taran's band of Commot men harried the undead forces and kept them from Annuvin where Gwydion was pursuing victory. At the top of Mount Dragon Taran found the enchanted sword Dyrnwyn and with it slew a single Cauldron-Born warrior, leading to the death of all the heretofore deathless warriors.
The Black Cauldron also appeared in The House of Mouse television episode, "House of Magic". Daisy Duck accidentally makes the House of Mouse audience disappear. When they ask the Magic Mirror for help, he tells them to check the prop basement for something magical to help them. Daisy and Minnie find the Black Cauldron; a sign on it says: "Who So-Ever Uses the Black Cauldron for Evil Will be All Powerful". The two suddenly, inexplicably evil females decide it's precisely what they need.
Daisy dresses as Maleficent and attempts to cast a spell. She ends up summoning the Cauldron-Born instead. In order to make them go away, she casts another spell. However, in the process, she makes the whole House of Mouse disappear. After everything is set straight by Jafar, Daisy attempts to use the Cauldron as a fondu pot, again summoning the Cauldron-Born. An ignominious final act for an instrument of such cold, awe-inspiring dread.