text: Peter Capaldi took over as the Twelfth Doctor following Smith's departure and debuted his first full episode in "Deep Breath". Capaldi made a cameo appearance in "The Day of the Doctor" and a guest appearance at the end of "The Time of the Doctor" after being cast in the role. He had also previously appeared in the Doctor Who episode "The Fires of Pompeii" and in the third series of spin-off series Torchwood, roles which were later connected to the Twelfth Doctor. Smith also held a minor role in "Deep Breath" in an appearance that was filmed prior to his departure. Coleman returned once more for the eighth and ninth series before exiting in "Hell Bent". Michelle Gomez appeared throughout the eighth series as an unknown character that was later revealed to be the next incarnation of the Master, this time going by Missy. Gomez also appeared in the two-part ninth series premiere. The Christmas special that bridged the two series featured an appearance by Nick Frost as Santa Claus, a role that was introduced through a cameo in the eighth series finale.
  Coleman's departure was followed by two Christmas specials ahead of the tenth series, the first of which featured a final appearance by Kingston and the second featuring the return of Matt Lucas as Nardole from the first, but this time in a starring role. Lucas continued this role through the end of the tenth series which also saw the introduction of Pearl Mackie portraying Bill Potts. Gomez recurred once more in the series and Simm reprised his role alongside Gomez in tenth series finale. The "Twice Upon a Time" Christmas special included the departure of both Capaldi and Mackie from the series. It also saw one-off appearances by David Bradley who had been cast as the First Doctor and Mark Gatiss as The Captain. Bradley was first introduced in the final episode of the tenth series. Coleman and Lucas both made guest appearances in the special as well. The Thirteenth Doctor, portrayed by Jodie Whittaker, was introduced at the end of the episode.