Idris!

   Idris is a human, who lived with her Uncle, Auntie, an alien called the House, and an evil green eyed Ood who works for the House called Nephew. When Doctor, Amy, and Rory visited the asteroid that they were living on, they meets the habitats (the ones i mentioned before), and the House gets TARDIS's matrix and puts it inside Idris's body. So Idris had the intelligence, and memories of the TARDIS and real TARDIS was getting controlled by the house. When the Doctor met Idris with the TARDIS's matrix, Idris makes the Doctor believe that she is the Doctor's Type 40, TARDIS. When they were talking, Amy and Rory were in the real TARDIS, and the house was keeping them in there, during that moment, it was really creepy, because House was keeping on messing up with Amy and Rory's minds, and Amy saw that Rory was really old, then she saw the dead body of Rory, while she was crying over Rory, the real Rory came out from the tunnel in the direction of Amy's back, which all were very confusing. Also, for on that one episode, the most funny thing in the whole season 6 happened (in my opinion). Idris asks the Doctor
 "Do you think that I am sexy?" and the Doctor says
 "Yes! You can say Sexy is your middle name!" and when they met Amy and Rory, Idris says
 "Hello, I am.......Sexy." I laughed out so hard during that part.

Idris is shown above

 Another good moment was that House says

 "Fear me, I killed thousands of timelords!" and the Doctor replies

 "Then fear me! I killed them all!"