- Blooper: The legendary scene where a Mauve Shirt is blasted by Graham Crowden as Soldeed and falls to the ground writhing in agony, his trousers splitting open. Later, Graham Crowden, whose performance in this story is pure Ham and Cheese, manages to crack up during his own death scene, although he just about manages to rescue it by turning it into a crazy Evil Laugh.
- Cast the Runner-Up: Graham Crowden was once a candidate to play the Fourth Doctor. Think about that.
- Creator Backlash: Graham Williams disliked the story, thinking it wasn't strong enough. It was made because there were no other scripts available. It was placed in the season's fifth slot in the hope that it would quickly be forgotten once the finale, "Shada", began transmission; unfortunately, this came back to bite him, since "Shada" would ultimately never be completed.It was a weak script and a weak programme, hence why we buried it at Number 5.
- No Budget: This story was basically produced with the loose change from the season's budget, so as to save all the money for the following story. Unfortunately, The BBC got temporarily shut down by industrial action before any substantial amount of the following story was filmed, meaning that this ended up being the grand finale for Graham Williams' era of the show.
- Permanent Placeholder: Soldeed's death scene was intended to be a camera rehearsal, but it was kept, despite (or because of?) the fact that Graham Crowden starts literally Corpsing in it.
- Prop Recycling: The vacuum-formed cryogenic pods used in "The Ark in Space" show up again.
- Scully Box: The Nimon wore ten-inch platform heels to give the impression of height.
- Throw It In!:
- Soldeed begins laughing hysterically during his death scene, while yelling "you are all doomed! All doomed!". The line was scripted. The laughter was (nearly literal) Corpsing. Graham Crowden had thought it was a camera rehearsal, but the take got used anyway, in part due to a lack of time, and in part because the director felt that it was still in-character.
- Malcolm Terris ad-libbed the line "WEAKLING SCUM".
- Tom Baker ad-libbed the scene where the Doctor gives K9 mouth-to-mouth.
Trivia / Doctor Who S17 E5 "The Horns of Nimon"