Warning: This article contains minor SPOILERS for A Quiet Place.

Getting the right design for the aliens in A Quiet Place took a long time, so it's no surprise that the monster's original look was much different than the final version that ended up on screen. From the beginning, screenwriters Bryan Woods and Scott Beck knew they wanted to make a horror movie without sound, but they never expected their nascent idea to become what it did. Part of that is due to the unique alien that was created for the film.

In most horror movies, aliens and monsters have simple motivations: to kill, or survive by killing. It's a tale as old as time, but the creative team behind A Quiet Place wanted to take their monster-based, post-apocalyptic story in a different direction. In this film, the monsters - which writer, director, and star John Krasinski confirmed come from outer space - are attracted to and repelled by sound. It's all about sound. That's what inspired their base design, as well as what they looked like in the end. But leading up to a final composition took quite a bit of time. In fact, they started designing the monster before entering pre-production, thanks to a suggestion from original Cloverfield movie writer Drew Goddard.

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According to comments made by the crew in the special features on A Quiet Place's home video release, the production team led by Jeffery Beecroft and concept artist Luis Carrasco, as well as many other crew members, started by making the monster blind since they were drawn to sound. Krasinski took inspiration from prehistoric fish, with Beecroft looking at nautilus shells. While all that eventually led to the final design, they originally had much bigger, more rigid monsters on their mind:

Some things to take note of that are similar between the original and final designs are that the aliens are blind and they have flaps on their heads. Krasinski was adamant about the aliens having flaps that open up and expose their ears. Just like how human ears curve, the designers tried to mimic that plating with the aliens' ears, giving them the ability to detect sound, directionally. Interestingly, the screeching sound the aliens made was initially considered too loud and uncomfortable that they had to significantly tone it down over time.

Krasinski's primary request to ILM and visual effects supervisor Scott Farrar was to hold the aliens back as much as possible. From the start, they wanted the experience to be more like Jaws in which the monsters aren't seen too much, which forces the audience to fill in the blanks with their imagination. But, the creatives really started to like what the production team came up with that they decided to show off the aliens even more towards the end of the film. Giving audiences one or two scenes to analyze the alien monsters goes a long way in helping them understand this movie's world.

More: Everything We Learned About A Quiet Place From The Blu-Ray

A Quiet Place is out now on digital HD and Blu-ray.