Pixar announces its upcoming films years ahead of time—because that’s how long it takes to make a full-length CGI-animated film. Or sometimes not at all.

Producers of live-action movies can rewrite scripts and reshoot scenes with actors. It’s much harder to change things after the fact in animation, which is why Pixar goes through many iterations of a film before they get to work on the final product. As Inside Out director Pete Docter told Fresh Air, they will animate basic stick drawings of scenes and add in music and dialogue to see if an individual scene or character is working.

Directors and animators receive feedback, and then change things during production if something isn’t working. Toy Story, for example wasn’t always about a toy cowboy and toy spaceman teaming up. It was initially about a one-man-band tin toy and a ventriloquist’s dummy Monsters, Inc. was set to be about a 30-year-old cartoonist haunted by monsters he drew as a child. It eventually became a movie about a monster city, and the relationship between one of those monsters and a little girl.

Only once has a movie in production not met Pixar’s self-imposed high standards: newt. Announced in 2010, it was to be about the last blue-footed newts on the planet that have to find each other, fall in love, and, uh, propagate. Unbeknownst to Pixar, and its corporate parent, Disney, 20th Century Fox had a similar movie set for release in 2011: Rio, about two endangered exotic birds that have to find each other, fall in love…

Pixar first delayed the release of newt to 2012, and focused on making Cars 2 instead, buying itself some time to rework the concept. But Pixar staff couldn’t find a way to make newt any less similar to Rio, and it was taken away from director Gary Rydstrom and given to Docter. Instead, Docter told Pixar bosses that he could possibly rewrite the movie…or they could make an idea he had about the emotions that live inside of a young girl’s brain.

After a lot of workshopping, that idea became Inside Out…and newt never made it to the screen.