Orddu, Orwen and Orgoch
Orddu, Orwen, and Orgoch are fictional characters in Lloyd Alexander's Chronicles of Prydain series.
They are three witches who live alone in the Marshes of Morva. Although their identities are apparently fluid and interchangeable, each persona has a distinctive appearance: Orwen wears a necklace of milky stones, Orddu's hair is adorned with many ornaments, and Orgoch's face is shadowed by a black cowl. They were the original owners of the Black Cauldron and lent it to Arawn, who used it to create zombie-like warriors, the Cauldron-Born. Later, they reclaimed it but were willing to relinquish it again in exchange for a magical price.
The Three Sisters, as they are known, are very mysterious beings, as one of the Fair Folk says to Taran, "It's more a question of what they are, not who they are." In one part of The Black Cauldron they turn from ugly, ancient hags and into three beautiful young maidens (from day to night). Orddu, Orwen, and Orgoch can also turn into each other, swapping their identities between them. They appear to take delight in tormenting intruders to their lair with talk of turning them into frogs and stepping on them, smiling the whole time as though they talk about jovial things. It appears that Orddu is the leader of the three, Orwen is the most cheerful and Orgoch seems to be the most disagreeable as neither of the other two sisters want to "be" her, and people seem most perplexed whenever she agrees to do something without grumbling. She also has a strong love for food and would devour anything on legs.
Despite their strange demeanor, the witches claim to not be evil (instead, being interested in things as they are) and indeed seem to seldom carry out their transformation threats, at least to Taran and his friends. They show a dislike of the Cauldron-Born, claim that Arawn spoiled their Cauldron for any of its other purposes, and seem pleased when Taran tricked several Huntsmen into sinking into a bog (it was also implied that they transformed several previous Huntsmen into animals). They also seem to consider stealing the Cauldron back from Annuvin no trouble.
In the books
In The Black Cauldron, Taran and his friends travel to the Marshes of Morva to find them, after learning that they are in possession of the Black Cauldron (which they were on a quest to destroy). The witches frighten and unnerve them, but then act very polite after learning that Dallben sent them. It is revealed that they found Dallben in the marshes as a baby and raised him as their own, however they were forced to send him away after he accidentally ingested a potion that made him their equal in intelligence (as they said, it was too much wisdom in their house). They tease the group during the night by leaving the Cauldron in plain view, but enchanted so that when Taran and his friends try to take it, they cannot release it. After watching this, the sisters release them and agree to sell the Cauldron. After asking absurd prices (such as memories or the North Wind) they are satisfied with a magical brooch that Taran has. They also warn Taran that the only way to destroy the Cauldron is to have a living being voluntarily climb into it.
In Taran Wanderer, Taran goes to the Marshes first when he is on a quest to discover his parentage. As he has no payment, the sisters refuse to directly answer the question, however they direct him to the Mirror of Llunet and leave him with the advice "The seeking counts more than the finding" and "every robin must scratch for his own worms".
In The High King, the witches make one final appearance near the end, this time in the shape of beautiful maidens (a form only glimpsed in The Black Cauldron). They give Taran a farewell present of an uncompleted tapestry which depicts his life's story. They tell him that they will leave on a journey of their own and when Taran asks for them to give him the answer of one final question as a last boon, they reply (a little sadly) "When in truth did we ever give you anything?" before vanishing.
The witches are Alexander's version of the Fates from Greek and the Norns from Norse mythology, and represent the mythological archetype of a Triple Goddess.
In film
Orddu, Orwen and Orgoch appear in Disney's 1985 animated film The Black Cauldron. Eda Reiss Merin voiced Orddu, Adele Malis-Morey voiced Orwen, and Billie Hayes voiced Orgoch. They serve as the minor antagonists, despite giving supporting information to the heroes about the nature of the Black Cauldron. (Orwen falls in love with Fflewddur Fflam in the film.)