"The New Mutants," the all-teen X-Men spinoff, was supposedly finished, screened and given a big thumbs-up from test audiences.

But after "It" became such a massive hit, Fox executives decided to ditch the "John Hughes meets Stephen King" vibe and make the film straight-up horror. At least according to an "insider report" over at The Tracking Board.

Director Josh Boone originally announced, "We are making a full-fledged horror movie set within the X-Men universe.... We're trying to do something very, very different." But then the studio reportedly demanded a PG-13 rating and less blood and gore.

After releasing a trailer that emphasized the scarier aspects of the film, Fox then reportedly decided to go "full horror" after all. That means extensive reshoots and a new release date: August 2019.

In other "New Mutants" rumors, Jon Hamm will no longer appear as Mr. Sinister in a post-credits tag. Instead, Antonio Banderas will be teased as a different villain.

"The New Mutants" was originally going to be released in April 2018.

[Via The Tracking Board]