Tim (Didn't You Kill My Mother?)
Tim was a Dalek time machine built by the Cult of Skaro on their homeworld during the Last Great Time War, in order to infiltrate the TARDISes on Gallifrey.
Like TARDISes, he was dimensionally transcendental, and his control room strongly resembled theirs. He could take on a humanoid form within his own dimensions, with a personality and motives of his own.
Tim believed that the Doctor never actually fought in the Time War, but heard many legends about him on Earth.
After the Time War, he met Arabella Hendricks, who recognised him (from later on in his timeline) as her consultant. Tim brought Mrs Hendricks, Valarie Lockwood and the Eleventh Doctor inside him, dressed up as an office, removed some of their memories, and pretended to be an impartial arbiter alongside "Mr Doctor".
After explaining his true identity to the Doctor, and restoring everyone's memories, he turned on Mrs Hendricks, killing her with the intention to install her AI in a new form to fulfil the rest of her known timeline. (AUDIO: Didn't You Kill My Mother? [+]Loading...["Didn't You Kill My Mother? (audio story)"])
