Question: Nardole is a fictional character created by Steven Moffat and portrayed by Matt Lucas in the long-running British science fiction television series "Doctor Who", a companion of the Twelfth Doctor, the current incarnation of the alien time traveller known as The Doctor, portrayed by who, which Scottish actor, writer and director, best known for playing the twelfth incarnation of the Doctor in "Doctor Who"?
Context: Bill Potts is a fictional character created by Steven Moffat and portrayed by Pearl Mackie in the long-running British science fiction television series "Doctor Who".  In the show's tenth series, starting with the first episode, Bill served as a companion of the twelfth incarnation of the alien time traveller known as the Doctor (portrayed by Peter Capaldi). "The Time of the Doctor" is an episode of the British science fiction television programme "Doctor Who", written by Steven Moffat and directed by Jamie Payne, and was broadcast as the ninth "Doctor Who" Christmas special on 25 December 2013 on BBC One.  It features the final regular appearance of Matt Smith as the Eleventh Doctor and the first regular appearance of Peter Capaldi as the Twelfth Doctor following his brief cameo in "The Day of the Doctor".  The episode also features Jenna Coleman as the Doctor's companion Clara Oswald, plus several enemies of the Doctor, including the Cybermen, Silence, Daleks, and Weeping Angels. River Song is a fictional character created by Steven Moffat and played by Alex Kingston in the British science-fiction series "Doctor Who".  River Song was introduced to the series as an experienced future companion of series protagonist the Doctor, an alien Time Lord who travels through time in his TARDIS.  Because River Song is a time traveller herself, her adventures with the Doctor occur out of synchronisation; their first meeting (from the audience's perspective) is his first and apparently her last.  In later appearances, River is a companion, romantic interest and eventual wife of the Doctor in his eleventh incarnation portrayed by Matt Smith.  River Song was created by "Doctor Who" writer Steven Moffat for the show's fourth series in 2008, under the tenure of executive producer Russell T Davies.  When Moffat took over Davies' duties as executive producer, he began expanding on the character's background, depicting adventures earlier in River's timeline, upgrading Alex Kingston from a guest star to a recurring actor in the series.  Other actresses have subsequently portrayed younger versions of the character. "The Impossible Astronaut" is the first episode of the sixth series of the British science fiction television series "Doctor Who".  Written by show runner Steven Moffat, and directed by Toby Haynes, the episode was first broadcast on 23 April 2011 in the United Kingdom, as well as the United States and Canada.  It also aired in Australia on 30 April 2011.  The episode features alien time traveller the Doctor (Matt Smith) and his companions Amy Pond (Karen Gillan) and Rory Williams (Arthur Darvill), and is the first of a two-part story, which concluded with "Day of the Moon". "The Husbands of River Song" is an episode of the British science fiction television series "Doctor Who".  First broadcast on BBC One on 25 December 2015, it is the eleventh Christmas special since the show's revival in 2005.  It is written by Steven Moffat and directed by Douglas Mackinnon.  The episode marks the return of Alex Kingston as River Song, making her first appearance alongside Peter Capaldi's Twelfth Doctor.  This also marks the first appearance of Nardole, who would become a companion starting from the next episode. Nardole is a fictional character created by Steven Moffat and portrayed by Matt Lucas in the long-running British science fiction television series "Doctor Who".  He is a companion of the Twelfth Doctor, the current incarnation of the alien time traveller known as The Doctor, portrayed by Peter Capaldi.  He initially appeared in the 2015 Christmas special "The Husbands of River Song" as a companion of River Song, before returning in the following episode "The Return of Doctor Mysterio", having become the Doctor's companion in the meantime. Peter Dougan Capaldi (born 14 April 1958) is a Scottish actor, writer and director, best known for playing the twelfth incarnation of the Doctor in "Doctor Who" and as spin doctor Malcolm Tucker in "The Thick of It", for which he has received four British Academy Television Award nominations, winning Best Male Comedy Performance in 2010.  For reprising the role in the spinoff film "In the Loop", Capaldi was honoured with several film critic award nominations for Best Supporting Actor.  He further took on the role of Paddington Bear's neighbour Mr. Curry in the family comedy film "Paddington"; he is set to reprise the role in "Paddington 2". Rupert "Danny" Pink is a fictional character created by Steven Moffat and portrayed by Samuel Anderson in the long-running British science fiction television series "Doctor Who".  He is a supporting character in the eighth series of the program, first appearing in the second episode, "Into the Dalek".  He appears alongside Peter Capaldi's Twelfth Doctor and his storylines stem primarily from being the colleague, and later boyfriend, of companion Clara Oswald, portrayed by Jenna Coleman.  He appears in every episode of Series 8 except for the series premiere "Deep Breath" and the third episode "Robot of Sherwood". The End of Time is a two-part story from the British science fiction television programme "Doctor Who".  It was originally broadcast on BBC One in the United Kingdom on 25 December 2009 and 1 January 2010, and is the fifth "Doctor Who" Christmas special.  This is the last story for lead actor David Tennant, who hands over the role of alien time traveller the Doctor to Matt Smith.  It is also the last "Doctor Who" story written and produced by Russell T Davies, who shepherded the series' return to British television in 2005 and served as the series' executive producer and chief writer.  Davies was succeeded as executive producer and showrunner by Steven Moffat. The Twelfth Doctor is an incarnation of the Doctor, the protagonist of the BBC science fiction television programme "Doctor Who".  He is portrayed by Scottish actor Peter Capaldi.  Within the series' narrative, the Doctor is a time travelling, humanoid alien from a race known as the Time Lords.  When the Doctor is critically injured, he can regenerate his body, and in doing so gain a new physical appearance, and with it a distinct new personality; this plot mechanism has allowed the Doctor to be portrayed by a series of actors over the decades since the programme's inception in 1963.  Capaldi's portrayal of the Doctor is a spiky, brusque, contemplative, and pragmatic character who conceals his emotions in the course of making tough and sometimes ruthless decisions.
Answer: Peter Capaldi