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".
The Doctor (Doctor Who)
The character played by Peter Cushing in the films "Dr. Who and the Daleks" and "" referred to himself as "Dr. Who". However, these films are not considered part of the same narrative continuity as the television programme, as they were based upon two television serials featuring William Hartnell and made considerable alterations to the characters of the Doctor and his companions.