12) “No Sir, All Thirteen!”
The Twelfth Doctor might just have the honour of possessing the single most exciting introduction of a Doctor ever. Though Peter Capaldi had been announced as the next Time Lord in August, he wasn’t scheduled to make his first appearance in the show until Christmas. So, it was a massive surprise when a familiar pair of eyebrows frowned their way into the big birthday celebration that was the 50th anniversary special “The Day of the Doctor.”
Finally having found a way to save Gallifrey, the Eleventh, Tenth and War Doctors unite all their past and future selves together for the big finale. “All twelve of them – I didn’t know when I was well off,” complains the Time Lord General. “No, sir – all thirteen!” his assistant corrects him. Cue a brief cut to Capaldi in his TARDIS.
In an episode that was stuffed full of fan-service, the shocking early appearance of Doctor #12 was one of the best.