What 8 horror movies looked like behind the scenes

• From "Scary Stories to Tell in the Dark" to the remake of "Pet Semetary," recent horror films have gone great lengths to scare viewers.
• "The Invisible Man" employed a performer in a green suit to throw Elisabeth Moss' character across a table while special cameras captured the terrifying movements of a monster the audience can't actually see.
• Jordan Peele's "Us" used facial replacement CGI to allow Lupita Nyong'o and the rest of the cast to act alongside their doppelgängers.
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Following is a transcript of the video.

Narrator: From stuntmen in green suits to jaw-dropping makeup effects, recent horror films have gone great lengths to scare viewers. But this innovation and technology aren't always visible on the big screen. So take a peek at what eight horror movies looked like behind the scenes.

This update to the 1933 classic found that the scariest things are what we cannot see. A stuntman in a green suit often stood in for the character on set. That came in handy for sequences like this, where Elizabeth Moss' character was thrown across a table. Moss' stunt double was attached to a rope, then the stunt performer in the green suit threw her across the table. The green-suited performer was erased later.

Meanwhile, for a scene in which actor Aldis Hodge had to fight the invisible villain, the actor fought himself instead. For some of the more action-packed moments, a motion-control camera helped follow the invisible man's every move.

"Us" went well beyond the classic split-screen technique seen in twin movies of the past to create the Untethered, who were the main character's doppelgängers. Legendary visual effects studio Industrial Light & Magic did extensive facial-replacement work. This sometimes involved using pieces of an actor's face and selectively swapping and combining them with parts of their double's body.

According to VFX supervisor Grady Cofer, knowing who the hero, or the character controlling the action of a shot was, was the key to figuring out which parts of a given shot needed to be swapped and grafted in postproduction. This feat was just as challenging for the cast, who had to perform each scene with both them and their doubles twice.

Meanwhile, to get this creepy shot of a young Adelaide being choked by her Untethered in the hall of mirrors, actress Madison Curry acted next to a cup on a stick, which was wrapped in green so it could be replaced with her double.

For this creature feature, the crew built an intricate flooded basement set in Serbia. The set was built to scale, and both actors and crew members actually had to crawl around to navigate it. The gators were almost completely CGI. According to director Alex Aja, it would have been unfeasible to capture the movement, speed, and viciousness of these animals with classic animatronics. Aja also said that when using animatronics, he would have had to restrict how he shot the film because of how these puppets are operated. As pointed out by Bloody Disgusting, he would have had to shoot from angles that hid the puppeteers.

The smash hit's greatest thrills and scares relied heavily on sound, or, as the title suggests, the lack thereof. The film's sound team, consisting of Brandon Jones, Ethan Van der Ryn, and Erik Aadahl, had to get really creative for the film's monsters.

Crab legs were used to capture their crackling footsteps. A combination of celery and lettuce was used for when a monster's ear would open wide. But nothing tops how they created the echolocation noises. The team used a stun gun and shocked a patch of grapes. After recording that sound, they edited it... and slowed it down so you could hear each individual click.

Special effects studio Spectral Motion created some of the most eye-popping monster makeup and costumes in recent history. Instead of using puppets, they used real actors to portray the film's monsters. Each monster was designed directly based on the minimal illustrations from the book. Famed creature performer Javier Botet starred as the toeless corpse. Botet's distinct physical characteristics informed the character.

Then there was Troy James, who gained fame as a contortionist in "America's Got Talent." He was perfect for all the bending and twisting required to play the Jangly Man. Even with all of the elaborate makeup, they of course needed a few CGI touches. For instance, when a character had a missing body part, that part of their body had to be covered in green.

For this remake of the Stephen King classic, animal trainer Melissa Millett and animal coordinator Kirk Jarrett had to train two cats, a live cat and an undead cat. A cat named Tonic was tasked with playing the living version of Church, as he was much more active and outgoing. Meanwhile, the older and calmer Leo played the undead version of the same cat. The two cats didn't look exactly alike, so they added some brown dye, which was safe for pets, to Tonic's fur so he would look identical to Leo.

Cats are one of the hardest animals to train for movies. One technique they used was targeting, which involves treats and a clicker. They would lure the cats to an object or area with a marker on it. Once they got there, they would hear [click] and get a treat.

Millett: Yay!

Narrator: They would then move the marker farther and farther away. During filming, Millett and Jarrett made sure the cats were acclimated to the set, as even the smallest factors, like temperature, can impact a cat's performance. The cats stayed close to the set and took walks in the woods, so they could get used to the environment.

And what about Church's bloody post-accident look? Well, Leo got his hair ruffled up and got covered with fake edible blood. And how do you make a cat give a frightening hiss? A snake toy can elicit the right response. Luckily, Leo was a natural hisser.

Part horror film, part black comedy, "Ready or Not" follows a new bride engaged in a deadly game of hide-and-seek. Throughout the film, actress Samara Weaving's dress goes through many stages of transformation, setting up quite the challenge for costume designer Avery Plewes. Plewes designed 24 wedding dresses. 17 were worn by Weaving, and seven by her stunt double.

The dress was actually five separate pieces that could be swapped in and out, and Plewes used an easily tearable fabric that was pre-rigged for the scene where Weaving's character rips her dress. Lace was chosen for the top of the dress because of the way blood would look on it.

The remake of the 1988 classic used old-fashioned animatronics to bring the terrifying doll Chucky back to the big screen. Jason Ward and the special effects wizards at MastersFX put together six different Chucky dolls for the film.

The inside structure of a given doll was filled with robotic pieces moving the figure around encased in a plastic exoskeleton, then covered in a foam latex skin. While mostly practical, some parts of it were enhanced with CGI, like the eyes, for example. It took three to four puppeteers to operate Chucky. He also had interchangeable hands, allowing the doll to pick objects up, like this knife.

What are some of your recent favorite horror movies? Let us know in the comments.