Ghostbusters: Frozen Empire Developed A Cool New Visual Effect For Slimer

"Ghostbusters: Frozen Empire" hits theaters this weekend (read our review here), and along with the returning casts of both the original "Ghostbusters" franchise and the new generation of specter catchers from "Ghostbusters: Afterlife," there's another ugly little spud making a comeback. That's right, Slimer is back on the scene, green and still kinda mean. Well, at least he's hungry, and if you interfere with his eating (even though he can't really consume the food), he gets super annoyed. Every time Slimer comes back, some of that ectoplasm comes with him, but this time, the visual effects department on "Frozen Empire" came up with some cool new movie magic that they've never achieved with this green ghoul before.

With a little help from Ivan Reitman, "Ghostbusters: Afterlife" perfected the recipe for the slime that is so often left behind by ghosts, so getting the ectoplasm residue right was the easy part. But for "Frozen Empire," the special effects crew created a new rig that allowed them to actually slime actor Finn Wolfhard ("Stranger Things") in camera without cutting. As special effects department head John Van Der Pool explained in the production notes for the film:

"[Slimer's] a proper celebrity and a classic character, but all the previous films have never managed to achieve sliming in camera. The camera cuts, they pour slime on the actor, cut back to the actor drenched. On this picture, we got the opportunity to develop a method of sliming Finn in camera: a self-contained pack that could do a slime splat on Finn's chest and on his back at the same time."

In "Frozen Empire," Trevor (Finn Wolfhard) is in the attic of the Ghostbusters firehouse trying to trap Slimer, which is never a good idea. When the ghost charges right through him, he gets slimed, which was achieved with that body pack. Thanks to "Mythbusters" mastermind Adam Savage, you can get a look at the effect in action below.

First, special effects senior technician Douglas McCarthy explained to Adam Savage and his Tested YouTube channel that the slime is created by using a liter of hot water, a liter of cold water, and 24 grams of a plant cellulose powder that is used to thicken foods like milkshakes. Combine that with 2.6 grams of green coloring powder used in children's toys, and you've got a goopy slime that is safe for the actors and has just the right consistency to feel so funky when it splashes all over you. There was actually an entire team that mixed over 1,000 gallons of slime for the movie. Of course, it's not all for Slimer, because the new ghost Pukey blasts a ton of it out of his weird little mouth.

Adam Savage's Tested

As you can see in the video below and the stills above, Savage was able to test the rig for himself. When the pack blasts the slime out with pressure tanks, it briefly appears in a ring shape around the actor thanks to the round bowls that deflect the slime as it shoots out of the rig. But eventually, the slime spreads, making it appear as if Slimer has just barged right through his body. In the final shot, visual effects artists digitally paint out the appearance of the rig that might be seen bulging through the shirt, and that's how you achieve in-camera sliming.

As for the actor getting slimed, Finn Wolfhard seemed to enjoy it. In the production notes, the actor said:

"Being slimed by Slimer could have been a lot worse. There was a cool rig made by the special effects department that shot slime out of my shirt and all over my face. They even put a little mint in it to give it some flavor. It really wasn't too bad — it was actually pretty fun."

Minty slime? Why aren't we getting any minty slime candy tied to the release of "Ghostbusters: Frozen Empire" in stores right now? We have Slimer popcorn buckets but not edible slime? C'mon, folks!

"Ghostbusters: Frozen Empire" is now playing in theaters.