The Twelfth Doctor is a medical procedure.
Doctor Who (series 8) . The series is the first to star Peter Capaldi as the Twelfth Doctor , the most recent incarnation of the Doctor , an alien Time Lord who travels through time and space in his TARDIS , which appears to be a British police box on the outside . Twelfth Doctor . He is accompanied in the eighth and ninth series by companion Clara Oswald ( Jenna Coleman ) .