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 regenerated for the first time. From the beginning, the Doctor was a mysterious figure. He appeared to be a frail old man and yet was possessed of unexpected reserves of strength and will. An early writers' guide by script editor David Whitaker describes "Doctor Who" as "frail-looking but wiry and tough as an old turkey". He obviously held tremendous knowledge of scientific matters, and yet was unable to pilot his TARDIS time ship reliably; his granddaughter Susan explained this by saying that her grandfather was "a bit forgetful"; but the TARDIS required expert piloting and guidance by the Doctor. Its