- Actor-Inspired Element: The Dylan cap that Dodo wears was owned by Jackie Lane.
- Cowboy BeBop at His Computer: Several modern viewers have claimed that Michael Gough plays the Toymaker in yellowface. Colour photographs of him in costume clearly show that this is not the case.
- Harpo Does Something Funny: In the script for "The Hall of Dolls", the infamous "Eeny Meeny Miney Mo" scene simply dictates that the King of Hearts closes his eyes and recites the rhyme, without giving any specifics. Campbell Singer was the one who decided on using a version that included the n-word.
- Missing Episode: All except the fourth, which was recovered by ABC in Australia in 1986. It survived because its title, "The Final Test", had led it to be mis-shelved among the station's cricket footage.
- No Budget: Because "The Ark" had gone over-budget, this one was made on the cheap.
- Prop Recycling: The Toymaker's robes (a stock outfit from the BBC's wardrobes) were previously worn by the titular explorer in "Marco Polo".
- Troubled Production:
- Most of the difficulties stemmed from the fact that it arose at a time of transition in the production office. Though commissioned by the team of producer John Wiles and script editor Donald Tosh, it was ultimately completed by the new team of Innes Lloyd and Gerry Davis. The two sides simply had very different ideas about how the story should proceed.
- All four episodes were in fact written three different times. Brian Hayles had delivered all four original scripts, likely in late 1965. Tosh and Wiles had immediately seen that the scripts could not be practically realised, and thus Tosh rewrote them entirely. By the time he was finished, though, he was no longer script editor. Davis, his replacement, now had to deal with the fact that Tosh had inserted the use of the title characters from a play called George and Margaret by Gerald Savory without obtaining permission. Since Savory was now Head of Serials, and had the power to veto scripts, he quickly rejected Tosh's approach.
- Davis, therefore, had to tackle the scripts again. These rewrites got Savory's approval, but the old production team were left wondering what had happened to their scripts. Tosh opined that Davis' approach was "much lighter, more pantomime" than his own. The results were no more pleasing to John Wiles, who wrote a memo to Savory after he had technically left the production office. In it, he claimed that the central battle of wills between the Doctor and the Toymaker had been downplayed to the benefit of new elements involving a more childish confrontation between the companions and the Toymaker's creations. Ultimately, Wiles would have liked to have seen the entire production halted, since its commissioning producer and script editor had gone and with them, the original, more adult intent of the story.
- However, the story's problems weren't over even after Davis's script had been recorded. After the transmission of "The Dancing Floor", The BBC had to field charges from the estate of Charles Hamilton that the character of Cyril was in fact meant to be Billy Bunter. The problem was exacerbated by the fact that actor Peter Stephens had ad-libbed the line "My friends call me Billy" during recording. Thus the BBC were forced to take a step never taken before or since: they had to have a special continuity announcement at the end of "The Final Test" which declared that the character of Cyril was not meant to be Billy Bunter, but merely a character like him.
- What Could Have Been:
- This came very close to being the show's first regeneration story. Producer John Wiles was having major problems getting along with William Hartnell, and decided to get rid of him via the Doctor being turned invisible for most of the story the idea being that when he appeared again, he would be played by a new actor. However, the BBC didn't approve of this plan in the least, seeing Hartnell as integral to the show, and when Wiles refused to back down they responded by firing him. Which in turn resulted in another case of this trope...
- The original storyline for the serial was very different, and much more adult and satirical in scope. After he was fired, however, Wiles massively overspent on the previous story as a final act of spite against his superiors, leaving the incoming team of producer Innes Lloyd and script editor Gerry Davis virtually nothing to make this story with. Davis therefore had to do a massive rewrite, cutting the story right down in order to accommodate filming with as many pre-existing sets and costumes as possible, changing the story's tone from satirical to just flat-out bizarre.
- Cyril was originally going to take the form of the Artful Dodger.
- The original script featured the main characters from George And Margaret, the gimmick of which was that although the entire story revolved around the imminent arrival of the eponymous characters, the play ended just as they were about to appear. When permission to use them was denied, their roles were filled by other characters.
- According to Donald Tosh, the commissioning script editor and (uncredited) co-author of "The Celestial Toymaker", the intention was that the Toymaker was, like the Monk who had predated him, a member of the Doctor's own race.
- Working Title: The Toymaker and The Trilogic Game.
Trivia / Doctor Who S3 E7 "The Celestial Toymaker"