Every episode of Doctor Who has much more than meets the eye so I like to put together a little post exploring links to the past and other things you might not have known about!
WARNING: Contains Spoilers
Last Christmas is the 10th Christmas Special in a row for Doctor Who. It is Peter Capaldi's first, Jenna Coleman's third, and Steven Moffat's fifth.
It is the 11th episode to air on Christmas day- the first was The Feast of Steven, part of The Daleks' Master Plan, which aired on 25th December 1965.
It is also the third christmas special in a row to feature actor Dan Starkey- he plays Ian the Elf. He also played his usual character Strax in The Snowmen (2012) and played several Sontaran warriors in The Time of the Doctor (2013).
Michael Troughton plays Professor Albert. He's the son of Second Doctor Patrick Troughton and his brother David Troughton has appeared in Doctor Who several times. The last time he was also a professor, Professor Hobbes in Midnight (2007).
Santa Claus is played by Nick Frost. His friend and regular collaborator Simon Pegg has also appeared in Doctor Who, as the Editor in The Long Game (2005).
The Doctor helps 'old Clara' pull a cracker which is a reference to The Time of the Doctor (2013) when Clara had to help the aged Eleventh Doctor pull one.
Clara is told not to salute. The Doctor has not liked being saluted for a while (see the likes of The Sontaran Strategm [2009]) and mostly recently protested against it in Death in Heaven (2014).
The episode plays homage to the film Alien (1979) and mentions it several times (in the dream scenes and on Shona's list). The film famously starred John Hurt, who played the War Doctor, who suffered a nasty end thanks to the titular alien.
