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
Doctor Who in the parody "The Five(ish) Doctors Reboot", which also starred two other former Doctors, Colin Baker and Sylvester McCoy, and cameo appearances from cast and crew involved in the programme, including showrunner Steven Moffat and Doctors Paul McGann, David Tennant and Matt Smith. The Doctor in his fourth incarnation has been represented on several episodes of "The Simpsons" and Matt Groening's other animated series "Futurama". There have also been many references to "Doctor Who" in popular culture and other science fiction, including "" ("") and "Leverage". In the Channel 4 series "Queer as Folk" (created by later "Doctor Who" executive