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 go home ("The Chase"), and their place in the TARDIS was taken by a future space pilot named Steven Taylor, who had been captured by the robot Mechanoids but escaped due to the Dalek attack. The Doctor met another member of his own race for the first time in the form of the Meddling Monk and had an adventure in Galaxy 4. During the siege of Troy, Vicki decided to leave the TARDIS to stay with Troilus, adopting the name Cressida. The Doctor and Steven were next briefly joined by Trojan slave Katarina and a security agent from 4000 AD