Matt Smith appears naked inside the TARDIS in the photos, with Jenna Coleman's Clara pointing in surprise in one picture.
The pictures arrive a day after BBC America aired an extended trailer for the special, titled 'The Time of the Doctor'.
The special will include classic Who monsters the Daleks, the Cybermen, the Weeping Angels and the Silence.
Doctor Who 'The Time of the Doctor' will air on Christmas Day (Wednesday, December 25) at 7.30pm on BBC One.
In the US, it will air on BBC America at 9/8c on December 25.
Gallery - The Time of the Doctor: