Big-Lipped Alligator Moment: The flower spout scene during Barnaby's second Villain Song, when he takes notice in the flower spout shooting out different torrents of water for some reason. It then goes back to the song like it never happened. (The real world explanation? They wanted an excuse for Ray Bolger to show off his dance moves. Any excuse.)
Moral Event Horizon: In the original operetta and all adaptations that include his wards, Barnaby attempts to kill them first by shipwrecking them and then abandoning them in the Forest of No Return in order to steal their inheritance. And that's only the start. Each adaptation offers even more possible moments:
He definitely crosses it in the 1997 animated version with his attempted murder of Humpty Dumpty.
The 1934 version had apparently crossed this line sometime before the film's plot even began most likely when he tried to blackmail Bo Peep into marrying him.
The 1961 version crosses it when he shrinks and imprisons the toymaker.
In the Disney version, one of the costumes' eyebrows falls down while the trees lead the characters off to Toyland. Not to mention, they obviously look rubber.
Then there's the 1986 version which takes it even further, one example being the Toyland set and costumes looking more like they belong in a cheap theme park attraction.
Mostly averted in the Laurel and Hardy version — despite being made in the 1930s much of what was seen was well-crafted and even the stop-motion soldier sequence is high quality. The only possible failure is the cameo by "Mickey Mouse" which is obviously a monkey in a costume, and some of the damaged soldiers in the final battle have their shoulders sit too high or other oddities as the actors had to wear prop elements to pull of headless or armless effects.
Unintentionally Sympathetic: The Toymaker's assistant, all he wants to do is make the toy production go as swiftly as possible, but then his boss not only messes with the machine, but states that all blame goes to him. Its hard not to feel sorry for him.
Values Dissonance: "I Can't Do The Sum." Basically Mary Contrary decides she has to marry Barnaby since she can't do the math on her bills and taxes... becomes jarring when one realizes the stereotype of girls being less than capable at math.