* CompletelyDifferentTitle:
** The French and European Spanish title, ''Merlin the Enchanter'', insists more on the {{Deuteragonist}}
** The Brazilian title is A Espada era A Lei, or The Sword was the Law
* CrossDressingVoices: In the Japanese dub, Creator/MikaDoi voices Arthur, and also overlaps with PlayingAgainstType, as she's normally casted for voicing very feminine roles.
* CutSong:
** The "Blue Oak Tree" song was cut from the film though still included in the soundtrack. It's a drinking song sung by the Knights of the Round Table about how stupid they are, doing nothing but drinking and jousting all day and night, not even knowing the significance of the Tree. The last few bars of the song appear in the film while Ector and Pellinore are toasting Kay's knighthood on Christmas Eve.
** "The Magic Key" was cut much earlier in production and it's not included anywhere, not even on the soundtrack. It was meant to highlight the central theme of the story "A noggin full of knowledge is the magic key". It even included Archimedes of all people singing along! It's only known because Music/TheShermanBrothers bemoaned it being cut and how "Higitus Figitus" despite having very little bearing to the plot became Merlin's signature song when they felt The Magic Key was better suited as it tied with the central theme to the film. An extra featurette on the DVD releases shows the brothers singing it live on the piano.
* DawsonCasting: Merlin describes Kay as being around twenty. Creator/NormanAlden was nearly forty.
* DevelopmentHell: A live-action remake was announced in 2015, but so far nothing has come out of it.
* HypotheticalCasting: Creator/MarkHamill has said that his dream role would be Merlyn in a possible LiveActionAdaptation.
* TwoVoicesOneCharacter: There were no fewer than ''three'' different voice actors for Arthur. And it's ''very'' noticeable. Rickie Sorensen was originally cast as Arthur/Wart, however, the long production schedule of an animated film meant that he aged up too much and his voice had clearly changed by the time he recorded his lines. With a tight budget and unable to pay for a new voice actor, director Wolfgang Reitherman cast his sons Richard and Robert Reitherman in the role, and while they sound very similar: young, squeaky, and a lot like [[WesternAnimation/TheJungleBook1967 Mowgli]] or [[WesternAnimation/TheManyAdventuresOfWinnieThePooh Christopher Robin]] (who were both voiced by their brother, Bruce Reitherman), the voice of 17-year-old Rickie Sorensen is obviously the voice of a teenager who's gone through puberty. The decision to keep voice clips from all three actors in the film, sometimes even in the same scene, causes some jarring viewing experience as Wart goes from a teenager's voice to a squeaky child's from one line to the next.
* WhatCouldHaveBeen:
** The Wizard's Duel in the film, judging by concept art, was going to be very similar to the original book, ending with Mim turning into an Aulay (a giant equestrian beast with an elephant's trunk) just before Merlin turns into the germ. Other elements for the Duel, also included Merlin transforming into a dog to bite Mim when she was a tiger and Merlin and Mim transforming into a frog and stork, respectively.
** As shown on the Blu-Ray special features and on Creator/DisneyPlus, an alternate version of the intro shows that Merlin has MerlinSickness like in the book. He and Archimedes live together so that they can document all the knowledge in the world due to the aforementioned "sickness". Mim was also to have a more prominent role in the story, as an {{Expy}} of Morgan le Fay, with her servant being the BlackKnight. Arthur's venture into Merlin's hut was due to Mim's interference with his archery lesson with Kay.
* WriteWhoYouKnow: Story artist and character designer Creator/BillPeet based Merlin on Creator/WaltDisney himself, noting that they were both cantankerous and argumentative, yet brilliant and ultimately lovable. In his preliminary sketches, Peet even gave the wizard Walt's nose.
----