A witch, and for a time the head of Morrolan's Circle of Witches. She was instrumental in his introduction to Verra, and assisted him in the formation of the circle in Blackchapel. According to Paarfi, forming a circle was Verra's idea, not Morrolan's. After Blackchapel was raided by followers of the god Tri'nagore, Arra accompanied Morrolan and Teldra on their journey West towards his ancestral holdings, eventually taking up residence at Castle Black and supervising the circle there.
Despite the fact that she was an Easterner, Arra had an exceptionally long lifespan, presumably granted to her by Verra in return for her service. It is unusual, but not unknown, for a very powerful witch to extend his or her lifetime using witchcraft.
It is unclear what happened to Arra. By the time of Issola she was no longer the head of the Circle of Witches, but it is not known if she was killed somehow, retired from this duty, has simply left Morrolan (perhaps to guide Blackchapel's restoration in her homeland), or eventually died of natural causes.