The Best Aliens in Horror Films to Entertain, Mesmerize, and Terrify

When a meteor hits the coast of Florida, leaving a strange shimmering dome to form around the strike zone, a U.S. Army Biologist must embark on a mission to understand what’s happening and to save her husband, who recently returned from a trip inside.

 Annihilation, based on the 2014 Jeff VanderMeer novel of the same name, tells the story of Lena and her team as they enter the Shimmer only to discover that all life merges and mutates while in its confines.

A phantasmagoria of grotesque beauty, the vaguely defined Shimmer offers everything from humanoid flowers and corpses morphed into bears. Think along the lines of The Thing (1982) but if it were on the cover of Vogue. 

An alien life form riding down to Earth on a meteor feels the most plausible of all alien invasions, and our chances against the Shimmer are likely good if we can tame our curiosity and keep clear of it. But considering that the theme of this movie serves to comment on the human penchant for self-destruction, the reality is that our odds are probably slim to none.

Killer Klowns from Outer Space paints a comedic picture of the chaos that ensues when a Circus Tent UFO crash lands on a small town, releasing a horde of alien clowns. 

First and foremost, the Killer Klowns get an unabashed A+ for branding, everything from their cotton-candy-shooting handguns to their popcorn bazookas and their murder methods flawlessly ties back to the crux of their clown nature.

It’s all vibrant imagery that has become essential horror iconography in the decades since its release.

However, it’s this strange integration of circus culture that, in a real-life situation, would probably also be the Klowns’ downfall. Part of what makes this horror-comedy laughable is the small-town victims of the Klowns.

They are painfully provincial, and if matched against just about anyone else, I’m not so sure the Klowns stand a chance.

The A Quiet Place movies are particularly terrifying because the Death Angels, the aliens featured in each of the three installments, have two very dangerous characteristics: they are lightning fast, and they strike exclusively based on sound.

The first two films cover what it’s like for a family with small children to live in this kind of post-alien apocalyptic world, and the first chronicles the death angels’ initial arrival on Earth. 

Think about the noises you’ve heard or just made yourself while reading this. It’s more than you realize. These movies prove survival is possible, but I’ll say this, it does not seem fun nor for the faint of heart. 

In the 2009 pseudo-documentary The Fourth Kind, Milla Jovovich plays Dr. Abigail Tyler, a psychologist from Nome, Alaska, who believes her patients and maybe even herself have been victims of alien abduction.

The movie gets its name from the Hynek classification scale of encounters with aliens, and it’s a reference to alien abductions that aren’t necessarily physical in nature but temporarily transform and suspend reality around you.   

What’s most terrifying about this movie is the absolute lack of aliens, and perhaps even more sinister, the way that symptoms of abduction both present as and are indistinguishable from mental health crises.

The aliens in The Fourth Kind are also the scariest because something like this feels the most real after accounting for a situation like Annihilation. An invasion of little green guys seems so far-fetched, but contact seems less so when we consider that it could be as simple as anomalies in memory or consciousness that we cannot explain. 

How would we fare against this kind of alien? To that question, I’d pose another one: how do we know for sure that they’re not already here?

The instigator of a decades-long battle that has spanned time and space, the Xenomorph is quite literally the greatest to ever do it who’s still doing it.

Nine films later, including the 2024 release Alien: Romulus directed by Evil Dead (2013) and Don’t Breathe (2016)’s Fede Alvarez, this creature is the backbone of a forty-five-year franchise in which it bests scientist after scientist who are victims of their curiosity.

The Xenomorph is both repulsive and terrifying with hyper-acidic salvia, regenerative properties, and a few extra retractable jaws’ worth of sharp teeth. It is perhaps the most iconic alien and the blueprint upon which most others in horror have been built. And best of all, for the most part, he likes to stay in space—unless he’s facing off against the Yautja, the warrior alien star of the Predator Franchise. 

If the Xenomorph migrated to Earth en masse and decided to pick a fight with us instead of the Predators, simply put, we’d be toast. Unlike the Death Angels, where it was possible to crack the code on cohabitation, I’m not so sure it’d be the same in this case. They are fast and they are angry.

According to canon, we found them, and judging how Earth responds in invasion movies, it makes sense they’re so hell-bent on retribution.

So, watch one, watch them all, but don’t make the rookie mistake of over-estimating yourself. To an over-confident skeptic, even cotton candy can be lethal.