John Hurt
From Tardis Wiki, the free Doctor Who reference
John Hurt played an unknown incarnation of the Doctor in TV: The Name of the Doctor. He is one of the few Oscar-nominated actors to appear in Doctor Who.
It is possible that this is either a PAST regeneration (Kept hidden after ninth) or a future regeneration.
Within the Doctor Who universe
John Hurt exists as an individual within the Doctor Who universe. In TV: Greeks Bearing Gifts, Toshiko Sato compared the body of a dead soldier with his heart ripped out to "that bit in Alien where that thing bursts out of John Hurt."
