The Doctor (Doctor Who) footage. Tom Baker did reappear, but as "the Curator", an ambiguously different character who he was not credited for playing. A voice actor, John Guilor, recorded a line of audio impersonating the First Doctor, for which he was credited as "Voice Over Artist". In other multi-Doctor stories, the multiple actors are all credited as "The Doctor", the exception being "The Three Doctors" (1972–73), which credited William Hartnell, Patrick Troughton and Jon Pertwee as "Doctor Who" as the 1972 serial preceded the practice of crediting the character as "The Doctor". In "Human Nature" (2007), the plot involves the Tenth Doctor altering
The Doctor (Doctor Who) of the Dead", confirmed to have been his name towards the end of "Forest of the Dead". The events of "The Time of the Doctor" make it clear that his people, the Time Lords, know his true name, despite referring to him by his chosen alias as "the Doctor", even in formal settings such as court. Although listed in the on-screen credits for nearly twenty years as "Doctor Who" or "Dr Who", the Doctor is seldom called by that name in the programme, except in a tongue-in-cheek manner. For example, in "The Gunfighters" the Doctor assumes the name of Doctor