The Seven and a Half Rules for Making Scary Aliens

Welcome back to Horrorhead, a fortnightly column where we explore the intersection of horror and scifi. For every bland, friendly Star Trek alien with a crinkle-cut french fry nose or waffle forehead, there are dozens of insanely scary aliens that could rip your face off. Certain alien characteristics, whether physical or psychological, are enough to put you into "no I will not jump during this dark corridor scene - shit I am now jumping" mode. But what exactly makes an alien truly horrifying, as opposed to just, you know, alien? Aided by Hollywood movie history, we've put together a definitive set of rules for making aliens that are guaranteed to freak you out — or at least make you queasy.

1. Double mouth, or double-wide mouth. (See: Alien)

As the Alien series taught us, there's nothing scarier than a really long, giant toothy mouth — especially if there's a second long, toothy mouth inside it. But the long, toothy mouth rule shows up in a lot of alien movies. In Slither, for example, a guy is taken over by an alien and one of the first things it does is elongate his mouth so that it practically stretches to his ears on one side. (Lopsided elongated mouths are a bonus — lopsided is always scary.)

Corollary: Drool

A scary alien must drool. Again, we know this from the Alien series where the drool flows like water. But since Ridley Scott first gave us full frontal drool in the first Alien flick, drool has been the sign of scary for all aliens. It says "out of control." Now, of course, we cannot imagine any monster without drool. See, for instance, Beowulf, where the monster's drool is one of the first 3D effects. And there's 3D drool coming up in Journey to the Center of the Earth, too. Dinosaur drool!

2. Collective Consciousness (See: Borg from Star Trek)

One of the scariest and most alien things we can imagine is a species that has collective consciousness, or group think. All their minds are connected together like a bunch of little networked Linux boxes, rapidly churning through all that knowledge to figure out exactly how to kill you. Plus, collectively conscious creatures can more easily coordinate an attack, because they are all in mental communication with each other all the time. And they might absorb you — think how scary it was the first time you saw the Borg chanting: "You will be assimilated."

3. Looks Exactly Like a Human (See: Invasion of the Body Snatchers)

Somehow it's scarier when an alien looks exactly like a human, or is camouflaged as one. Even though Men in Black wasn't exactly scary, there was something uncanny when the alien took off its human skin and revealed its true face. And of course one of the reasons Hollywood has remade Invasion of the Body Snatchers four times in the past 50 years (Invasion was the most recent one) is that it's so freakin creepy that the aliens look perfectly human — except for the fact that they have no emotion. We will not, however, speak of the human-camo farting aliens from Doctor Who.

4. Treats Humans the Way Humans Treat Animals (See: Predator)

The infamous Twilight Zone tale "To Serve Man" packs all its punch into one single idea: the aliens have a cookbook ALL ABOUT EATING HUMANS! They look at us the way we look at chickens! The same idea lurks at the heart of popular franchise Predator, where the whole conceit is that the alien has just come to Earth on a safari to hunt human game. Where's the respect? 5. Polymorphous (See: The Thing)

If there's anything scarier than an alien that looks just like a human, it's an alien that can look like whatever it wants. Although the shiny, pretty aliens in Abyss wind up being our friends, they are super scary at first because they can morph into any shape they want. And of course what makes the thing in John Carpenter's version of The Thing so scary is that it can turn any body part into chunks of alien — human heads sprout legs, blood jumps up and runs around the room, people grow dog heads. Whoa. Same goes for the aliens in my personal favorite alien movie, Society, where a bunch of rich Beverly Hills types turn out to be polymorphous creatures who love to have giant orgies where they merge into a big room full of goo and eat humans.

6. Wants to Mate With Humans to Produce Scary Hybrid Offspring (See: Species)

The fear of an alien being who wants to mate with you probably goes back thousands of years, but in terms of current pop culture we can probably trace it back to H.P. Lovecraft's Cthulhu stories of the 1920s. Remember, one of the scariest things about Cthulhu's spawn is that they are mating with humans, producing strange, fishy-looking humans who eventually go back to the sea. Combining this rule with rule 3 (looks human) is the Species franchise, where a super-hot alien lady goes around humping unsuspecting men for their seed and then killing them in flagrante delicto.

7. Buglike (See: Independence Day, Starship Troopers)

Buglike aliens are a staple of the genre. Even the aliens of Alien are buglike, with their hard carapaces. Bugs are so scary-looking already, and we suspect they may also participate in rule 2, having collective consciousness. In fact, "buglike" has become shorthand (sometimes lazy shorthand) for "scary alien," which is why you see so many depictions of aliens with feelers or antennae on their heads. Bug aliens show up in some of the most generic scifi flicks like Independence Day and Starship Troopers. But there are buggy aliens in more highbrow places too, like the Ender's Game series, where Earth is battling (and ultimately genociding) a buglike race.