The Doctor (Doctor Who) credits Tennant as "Doctor Who". The credit reverted to "The Doctor" for 2005's Christmas special "The Christmas Invasion" and all subsequent stories at Tennant's request. Matt Smith, Peter Capaldi and Jodie Whittaker have continued to be credited as "The Doctor". John Hurt plays a mysterious past incarnation of the Doctor in the 50th anniversary special "The Day of the Doctor", with minor roles in "The Name of the Doctor" and mini-episode "The Night of the Doctor", created as a "mayfly Doctor" by Steven Moffat. In the television episodes, he is credited as "The Doctor", but he is introduced as "The
First Doctor life, the Doctor can regenerate his body; in doing so, his physical appearance and personality change. Hartnell's Doctor is the Doctor's "original" form. The rejuvenation, initially referred to as a "renewal," was introduced when Hartnell needed to leave the series, and consequently has extended the life of the show for many years. His original companions were his granddaughter Susan (Carole Ann Ford) and her schoolteachers Ian Chesterton (William Russell) and Barbara Wright (Jacqueline Hill). The character occasionally appeared in the series after Hartnell's death, most prominently in 1983's "The Five Doctors" where he was portrayed by Richard Hurndall, and two