Auntie was a patchwork person who aided the sentient asteroid House in bringing TARDISes to him.
Biography
Auntie was transported to House via a rift in spacetime, where she lived with Uncle, Nephew and Idris.
Auntie was composed mainly of stolen body parts from Time Lords and other creatures that found themselves in the junkyard. She, Uncle and Nephew were kept alive by House in return for doing the latter's bidding.
When House left the asteroid, Auntie, alongside Uncle, were doomed to die, as they both relied on it to remain alive. Both she and Uncle remained stoic in the face of their deaths and she casually refered to it as "time for auntie and uncle to pop off." She died shortly afterward and was outlived by Uncle for a few seconds.
Auntie was in possession of the Corsair's left forearm and hand at the time of her death, which was recognizable owing to the ouroboros tattoo which he had for each regeneration. She referred to the arm as being "a good arm for [her]." (DW: The Doctor's Wife)