J.K. Rowling’s Fantastic Beasts and Where to Find Them will — as the title suggests — involve magical creatures.

So far we know that Pokémon trainer beast enthusiast Ash Ketchum Newt Scamander will be capturing creatures with his Pokéball keeping creatures in his suitcase as he studies them for the greater good. In the movie this case will be accidentally opened “just a smidge,” leading some beasts to escape, causing havoc in 1920s New York. The No-Majs and the wizarding government MACUSA probably won’t be happy about it!

The release of a trailer and several stills have yet to yield a look at an actual beast in the movie. One reason for the absence may be that their special effects just aren’t complete.

Speaking with Total Film, producer David Heyman has revealed that there will be no animatronic creatures in Fantastic Beasts and Where to Find Them. They will all be created by computers.

“They’re all going to be digital,” he said (via Snitch Seeker). “These are extraordinary creatures. I don’t know how they could do this practically -– as wonderful as animatronics are, you can’t get the detailed movement or flexibility that you can with the digital universe. We have explored animals in the real world. We’ve done a lot of research on movement and look because we want to make our creatures grounded. They should seem like they really could exist, so they’re not just pure fantasy.”

There must be a lot of pressure to get these beasts right, because they could really make or break the film. And they’re going to have a high bar to live up to: Heyman’s comments come as Disney prepares to release their “live-action” adaptation of The Jungle Book. I put “live-action” in quotes because the creatures in the film are completely CGI, and by all accounts, Disney has done an amazing job making these animals look completely realistic. Just take a look at the trailer and you’ll see what I mean:

While technology has allowed filmmakers to achieve realistic visuals, no one can deny the charm of animatronics. Just look at Star Wars: The Force Awakens and Lucasfilm’s decision to use as many practical effects as possible (BB-8! BB-8! BB-8! And all those other creatures).

Orlando’s Wizarding World of Harry Potter: Diagon Alley land may offer a couple of clues as to what the beasts will look like. Two years ago we reported that a shop in the expansion potentially has creatures who may appear in the Fantastic Beasts movie.