Disney didn't want to call The Nightmare Before Christmas a Disney movie before it got really popular
The Mouse House was even hesitant to call the iconic stop-motion musical a Disney film, said director Henry Selick

Disneyland’s “Oogie Boogie Bash” Photo: Jeff Gritchen/MediaNews Group/Orange County Register
We all know Disney loves to make a buck (and multiple sequels) off of any IP that gets butts in seats and kids in stores. Still, you might be surprised to hear that the Mouse House didn’t initially think a seven-ish-foot-tall skeleton and a sack full of pests were as safe a bet as Cinderella or The Lion King. While stop-motion creep-fest The Nightmare Before Christmas is nothing short of a classic 30 years on from its original release, execs apparently used to be pretty spooked by the film.