Back in 1983, long before Spike Jonze showed us that giant monsters look best as practical effects in sun-drenched forests, Disney owned the rights to Maurice Sendak's Where the Wild Things Are and were apparently considering making it an animated film. John Lasseter, then Disney emloyee and later founder of Pixar, did some tests to see if it would be feasible to use hand-drawn character animation over 3D backgrounds.
Studio heads decided the technique was "too expensive" and "what they do on Futurama," and Lasseter was fired shortly after. But now, thanks to internet, we can see one of those early tests:
Good thing we figured out computers are worthless to animation so early on. It would have been a shame to waste any more time with that.