Doctor Who: The Giggle

This episode marks the return of the Celestial Toymaker for the first time in fifty-seven years. There were a few attempts to bring him back before this episode. His creator, Brian Hayles, pitched an outline called 'The Eyes of Nemesis' in 1975 which would've pitted The Fourth Doctor against The Toymaker. The outline was rejected. He came close to returning in 1986 in an episode called 'The Nightmare Fair' which would've pitted him against The Sixth Doctor. However, the episode was cancelled when Doctor Who (1963) was put on an 18-month hiatus before filming began; the proposed story was adapted into a novel by Target Books in 1989, and an audio drama by Big Finish Productions in 2009. The third attempt to bring him back was in the Children in Need special Doctor Who: Dimensions in Time (1993) where he was the main villain of the special in an early draft of the script. However, his original actor Michael Gough declined to return so he was replaced by the Rani, played by Kate O'Mara.

Neil Patrick Harris, who is an accomplished amateur magician, performed the card tricks of the Toymaker himself.

John Mackay had already played John Logie Baird for Russell T. Davies in his ITV drama Nolly (2023). It was whilst writing the drama that Davies learned of the genuine Stooky Bill dummy and his part in the inventor's early television trials at 22 Frith Street, London.

While it is widely known that Doctor Who (1963 - 1989) was one of the main reasons that David Tennant wanted to become an actor, Ncuti Gatwa has said multiple times that Tennant is one of the main reasons why he wanted to become an actor. So in this episode, you have a man who is acting alongside the man who made him want to become an actor, who's playing the role that made him want to become an actor.

Donna is surprised that she wasn't the first redhead to travel in the TARDIS, however Melanie Bush was not the first, either. That distinction belongs to Vislor Turlough, one of the Fifth Doctor's companions.