Doctor Who
Thirteen actors have headlined the series as the Doctor. The transition from one actor to another is written into the plot of the show with the concept of regeneration into a new incarnation, a plot device in which a Time Lord "transforms" into a new body when the current one is too badly harmed to heal normally. Each actor's portrayal is unique, but all represent stages in the life of the same character. Together, they form a single lifetime with a single narrative. The time-travelling feature of the plot means that different incarnations of the Doctor occasionally meet. The Doctor is currently portrayed by Jodie Whittaker, who took on the role after Peter Capaldi's exit in the 2017 Christmas special "Twice Upon a Time".
Paul Darrow
Paul Darrow (born Paul Valentine Birkby on 2 May 1941) is an English actor best known for his portrayal of Kerr Avon in the BBC science fiction television series "Blake's 7". He also guest starred twice on "Doctor Who", playing Captain Hawkins in the serial "Doctor Who and the Silurians" which was transmitted in 1970 and Maylin Tekker in the serial "Timelash" which was transmitted in 1985. He is also the voice of "Jack", on independent radio stations JACK FM and Union JACK, whose lines include dry-witted comments pertaining to current events.