9. Every Single Bubble Had To Be Hand-Drawn - The Little Mermaid
The Little Mermaid is one of Disney's most visually stunning 2D animations, in large part because Ron Clements and John Musker pushed the boundaries of what their human animation team could come up with.
The film was made years before digital simulations could automatically recreate bubbles, and while animators would typically save themselves time by photocopying repetitive objects rather than drawing them all by hand, Clements and Musker insisted that every single one be drawn the hard way.
As such, the poor animators had to draw more than a million bubbles for the film, and so intensive was the workload that Disney ended up farming most of the bubble drawings out to China-based firm Pacific Rim Productions.
This ended up causing a massive complication due to student protests which took place during production in Beijing, where Pacific Rim was based.
The drawings were locked in the company's vault mere blocks away from where the most violent demonstrations and conflicts were taking place.
And so, there was a very real fear that the completed work - estimated to be roughly one-third of all the bubbles - could get lost due to fires, looting, or general destruction.
Thankfully that wasn't the case, but the filmmakers' insistence that every bubble be drawn by hand ultimately proved even more of a stressful ask than expected.