Max Fleischer's Gullivers Travels is extremely unstable in its animation quality. Some scenes are fairly well drawn and animated (the first scenes with the Kings, Gulliver's meticulously rotoscoped animation) to absolutely abysmal (i.e., the scene where Gabby falls into Gulliver's hand early in the film, some of the crowd shots). This was undoubtably a result of its rushed deadline, plus the mixed influx of East Coast and West Coast animators working on the film, some of whom were literally hired off the street and given animation cram courses in a matter of hours before getting to work. As such, the film suffers not only from a mix of sloppy and professional animation, but also floaty, mushy inbetweens and sloppy inking. There are even some design-wise off model moments (i.e., Gabby's eyes tend to be drawn differently depending on the artist). There's a reason Walt Disney quipped that "We can make a better film than that with our second-string animators."
One example would be a scene in Pinocchio. When Pinoc sets his finger on fire and Gepetto tries to put it out, watch his cap—it disappears and reappears several times throughout the scene!
During the first chase scene from The Aristocats, one of the two dogs attacking Edgar mysteriously gains a collar just so he can be yanked upwards by the windmill's blades.
Also, at the end of the film, during the scene where the cats stuff Edgar into the very crate he was going to use to ship Duchess and her kittens to Timbuktu with, and later pushing said crate out the door, there is no lock on the crate's lid as it was already removed by Roquefort the mouse, but when the movers finally come to pick it up and take it away, the lock for some reason was already back on the crate's lid!
Merry and Pippin switch between blonde and brown hair
Humans outside the main cast are poorly animated
Gandalf the White briefly returns to his old clothes before entering King Théoden's palace
Gollum gets really skinny looking at the end of the film
When the animals escape from the fire in Bambi, a mother raccoon pauses after emerging from the river to lick her baby dry. The baby disappears. However, this was fixed for the DVD releases.
Some prints of the movie have said baby raccoon suddenly reappearing in another random spot in the shot, lessening the Fridge Horror, but still looking a little tacky.
Prince John, the Big Bad of Disney's Robin Hood, constantly gains and loses rings throughout the entire film.
Lampshaded by Prince John at the archery tournament.
Prince John: No, no, I lose more jewels that way...
Also, Maid Marian for some reason becomes unusually tall for a fox whenever she is dancing (guess which film they got her dance moves from!).
The circus locomotive from Dumbo for some reason, actually gains and loses train cars as it is travelling across the countryside. The only time we actually see the locomotive with the correct number of train cars is when it is crossing the bridge before climbing up the mountain. Also, during the scene where the circus train get loaded up, a circus wagon on one of the train cars changes color, as with one of the crewmen's outfits.
Also, during the scene where the Delivery Stork that is carrying Dumbo is looking down at the Southeastern United States, there are no clouds above the map, but when the stork finally descends, clouds inexplicably appear above said map.
And at the end of the film, when Mrs. Jumbo is released from captivity and riding inside her and Dumbo's private train car, the ruffles on her hat actually disappear just right when Dumbo flies into said train car and into his mother's trunk.
And let's definitely not even get us started on how many elephants were used for the "Pyramid of Pachyderms" scene.
One scene from Pocahontas shows a closeup of John Smith's boots (Meeko the raccoon is standing between them). For some reason, there's an empty void on the heel of Smith's left boot!
Flit's wings disappear in one scene.
Also when Pocahontas is showing John how her tribe says hello, pay attention to her lower back. Her hair does not appear between her elbow and lower back when it really should. It disappears and reappears between frames.
During the "You Can Fly" number from Peter Pan, when Peter Pan and the Darling children fly away from the Big Ben clock tower before finally arriving at Neverland, Wendy Darling's face actually disappears for a split second.
Toward the end of The Hunchback of Notre Dame, during the scene where Esmeralda pulls Phoebus from underwater, when one of Frollo's henchmen shoots Phoebus off his horse, making him fall into the water, the arrow is in the back, but when Esmeralda pulls him out, the arrow is in the front!
Snow White and the Seven Dwarfs. Interestingly, it's not quality that suffers in this example - the animators seem to just forget what they're supposed to be drawing. When the forest animals are following Snow White into the Dwarfs' house, a rabbit hops behind another rabbit and comes out as a squirrel! Disney was so embarrassed it had a demo video taken off YouTube.
The Thief and the Cobbler: The sequences added after the firing of creator/director/writer/animator Richard Williams were done on a much lower budget by several different animation studios around the world. Particularly bad, as the original animation by Williams had extreme effort put in it, making the cheaper scenes look terrible in comparison.
At the end of Cars during the final race scene, the King's eyes actually change from brown to blue when he is crashed by Chick Hicks. His eyes then turn back to brown just right when he is helped by Lightning McQueen into crossing the finish line.
At the start of the race in Japan in the sequel, Lightning mysteriously gains his party wheels at the starting line for a few seconds, but is wearing his racing wheels for the remainder of that race.
During the first Elephant Patrol scene from The Jungle Book, Colonel Hathi accidentally breaks his bamboo cane, but in the next scene, Hathi's cane is inexplicably repaired!
The BIONICLE movies combine this with Special Effects Failure with tiny Nuju in the first film, the disfigured Visorak in the third film, and the robot body of Mata Nui in the fourth film, which is both lighter in color and smaller compared to its surroundings than in other media featuring it.
A peculiar example are the Vahki soldiers from the second movie. Of the six types, only two appear — Rorzakh the black Vahki, and the brown Zadakh Vahki. Yet they are both shown carrying the tools of the Vorzakh, the green Vahki type. In fact, a lot of the movie models made very liberal stylistic changes to the toys, and employed many shortcuts (like using the same few animation models for the background extras), even if other media used some of the toy-designs as plot points, so a handful of the movie designs were eventually declared non-canon.
From Mask of Light, the Matoran crowd in Onu-Koro is made up of blocky, texture-lacking non-finalized models, the sort they use for test renders.
Happens in almost every scene in Transformers: The Movie, despite having a higher budget than the series itself. Most egregious examples include Unicron's overall size in comparison to a planet (I.E he's able to stand on top of Cybertron in one scene while in the previous scene he was bigger then said planet), several mis-colorations (Starscream's chest when mocking the fallen Megatron, Rumble being the same color as Frenzy in one scene) and characters being in a place when they shouldn't be (Swoop's leg at Autobot City, Thundercracker and Skywarp at Starscream's coronation, the Insecticons in several scenes) amongst several others.
Unicron's appearance noticeably changes as well, as his first transformation sequence had been completed before his iconic robo-bearded face was finalized.
Cinderella, for some reason, actually doesn't have any toes. However, the third movie gives her feet proper details.
Also, at the end of the film, Cinderella's wedding dress is supposed to have long sleeves, but when she and Prince Charming get inside the carriage, her dress has short sleeves like her ballroom gown.
The Lion King has Nala's eye color switching from green to blue during the same scene.
Speaking of Atlantis, pay very close attention to Kida's bracelet. When she loses it at the very beginning of the film as a result of her mother the Queen pulling it off her wrist so that the Crystal can sacrifice her, the beads are arranged as pink, blue, pink. When she finally retrieves it at the end of the film shortly after saving Atlantis from a lava flow and transforming back from her crystalline form, the beads on her bracelet are now arranged as blue, pink, blue (similar to the feathers attached to the backs of the tiaras worn by the queens). Also, during the finale the patterns on Kida's dress actually shift just right after the stone face representing her late father flies away in the sky, and the sash hanging down from the front of her dress mysteriously vanishes shortly afterward.
This◊ shot from Aladdin managed to spawn a Tumblr meme around this trope as it applies to Disney films. (Look up "DIDNEY WORL".)
The Secret of NIMH 2: Timmy to the Rescue features a scene where Timmy hugs his mother in a way that would only work if Mrs. Brisby's neck had the ability to be stretched back while her head and body stayed in the same place.
An American Tail, of all places, does this briefly during the scene where Fievel finds himself in a bottle. Right after Fievel sees a partially finished Statue of Liberty and before washing up on shore, he doesn't look much like himself and his fingers are bigger.
The sequels to All Dogs Go to Heaven are inconsistent with the dogs' toe pads. Sometimes they have them, and sometimes they don't.
The SpongeBob SquarePants Movie does this intentionally, with Spongebob and Patrick spending most of their screentime off model to make humorous expressions.
Some of the cars appearing in the song "Worthless" from The Brave Little Toaster aren't even moving their mouths as they are singing after the Magnet drops them one by one onto the conveyor belt leading to the Car Crusher.
Speaking of, there's plenty of moments where the cords of the characters either shrink or disappear completely.
Mulan starts off being drawn with long eyelashes and thin eyebrows, but when she cuts her hair to complete her disguise as a male soldier so that she can join the war against the invading Huns, her eyelashes disappear and her eyebrows grow bigger. When Mulan changes back into more feminine-looking clothes for the final battle against Shan Yu in the Imperial Palace, her eyelashes grow back, but her eyebrows still remain huge and bushy.
Possibly she's wearing mascara during the feminine scenes, and has stopped plucking or otherwise altering her eyebrows since joining the army.
In one scene near the beginning of The Fox and the Hound, when Tod is playing with a cow's tail and udders he is unusually chubby and fluffy and his face looks different.
In Beauty and the Beast, Belle seems to have two different character models - one for her one-on-one scenes with her father, and another for the rest of the film. This may be a side-effect of a (reportedly) rushed production.
In Lilo & Stitch, Jumba's head changes size in some of the scenes, especially near the end. Mainly because the ending had to be changed at the last minute, and they had to rush it through animation to make their deadline.
In Aladdin: The Return of Jafar when Abu climbs on Aladdin's shoulder as he hides Iago from Jasmine he looks more like a little bear with a long tail.
The movie itself is considered by many to be nothing but one big moment of off model. Not helping its case is the abrupt changeover from Disney's Australian studio to their Japanese counterpart halfway through, denoted by the abrupt, noticeable switch from Aladdin's palace robes to his "street rat" get-up at the end of "Forget About Love".
In Hercules whenever Hercules suffers Clothing Damage, his tunic constantly repairs itself between frames. And during the scene where he is mobbed by fangirls, the ripped part of the tunic switches shoulders constantly between frames. Additionally when Hercules is about to jump into the River Styx - when he first dips his hand in the water, it's as if it's a riverbank. However a few seconds later they're suddenly on a cliff that Hercules must dive off.
Elsa's hair briefly clips through her arm when she lets her hair down during the "Let It Go" sequence in Frozen. However, this was done on purpose by the animators, as the action would have been impossible to pull off otherwise.