Doctor Who
The Master is a renegade Time Lord. He is the Doctor's nemesis. He was conceived as "Professor Moriarty to the Doctor's Sherlock Holmes". The character first appeared in 1971, played by Roger Delgado. He continued in the role until his death in 1973.  The Master was briefly played by Peter Pratt and Geoffrey Beevers until Anthony Ainley took over. He continued to play the character until Doctor Who's "hiatus" in 1989. The Master returned in the 1996 television movie of Doctor Who, played by Gordon Tipple in the ultimately unused pre-credits voiceover, then Eric Roberts. The Master was in the three-part finale of the 2007 series, portrayed by Derek Jacobi. He regenerated into John Simm at the end of the episode "Utopia". Simm next appeared in the last (and two-part) episode of the Tenth Doctor in 2009/2010. He then regenerated off-screen into a Time Lady (Michelle Gomez), who returned for the Twelfth Doctor's first series in 2014. In Whittaker's run, the Master returned as Sacha Dhawan in 2020 and 2022