6) Scream of the Shalka
On the 40th Anniversary of Doctor Who, a time when the show was not on TV and was only kept alive through fans writing novels and creating audio plays and books, an animated series called Scream of the Shalka was created that was considered canon at the time.
Today, it’s most notable for the people that were involved with it rather than the story itself. For one thing, it was created by Paul Cornell, who went on to write the critically acclaimed Father’s Day and the Human Nature/Family of Blood two-parter in the revived series.
The Doctor was played by Richard Grant, who went on to play The Great Intelligence in The Snowmen and The Name of the Doctor. The companion was voiced by Sophie Okonedo, who played Liz 10 in The Beast Below and The Pandorica Opens. Finally, Derek Jacobi was The Master, who reprised the role in Series 3’s Utopia.
Perhaps the most interesting casting bit though is David Tennant’s uncredited role as a caretaker. How’s that for trivia?