
Spoiler Warning: There are spoilers ahead for the following Star Trek productions: The Original Series Season 1, The Next Generation, Deep Space Nine, First Contact, Enterprise, Discovery Seasons 1-2, Picard, Strange New Worlds, and Section 31.
It’s Spooktober, the scariest month of the year! And what better way to celebrate than to talk about… Star Trek? That can’t be right!
Star Trek has dipped its toes in the horror genre on a few occasions – including in recent years. But that’s not really what I want to talk about today (though I suppose we’ll touch on some horror-tinged episodes as we progress). Instead, I want to take a look at a few of the franchise’s aliens that could have been terrifying… if their respective storylines had been written that way. In short, these are aliens that have horror potential, but because Star Trek is what it is… they never really managed to scare me!

As usual, I like to give a small caveat. Everything we’re going to talk about is the entirely subjective, not objective opinion of just one old Trekkie. If you hate all of my ideas, think I’ve totally misunderstood something, or I exclude a faction that seems blindingly obvious to you… that’s okay! There’s plenty of room in the Star Trek fan community for polite discussion and respectful differences of opinion, and I share this piece in that spirit.
Now, a bit more detail is necessary on this idea, methinks!
Star Trek can do horror – and it can do horror-themed stories exceptionally well. But Star Trek is not primarily a horror franchise, and we often explore aliens through the lenses of exploration, first contact, diplomacy, friendship, curiosity, or war. There are many stories involving contact with alien races – and alien “monsters,” to use some Halloween-adjacent lingo – but most of them treat aliens as potential new friends rather than terrifying, incomprehensible adversaries. And even in stories where an alien is villainous or powerful, Star Trek tends to go for either some kind of peaceful resolution or more of an action-heavy tone rather than all-out horror.

But there are some aliens, introduced throughout the franchise’s fifty-nine-year existence, which could feel genuinely terrifying if they were dropped into a story that really went for a horror tone. A great example of this is the Gorn: The Original Series depicted the Gorn captain as an enemy for Kirk, sure, and Kirk even describes the Gorn as a “monster” in the episode. But Arena (the only episode prior to Enterprise where the Gorn appeared) was a piece about exploration and understanding – with a healthy dose of action thrown in, of course.
But Strange New Worlds took the Gorn in a whole new direction, ramping up their more monstrous qualities, and leaning into a style of storytelling not unlike that seen in the 1979 classic film Alien. This is the kind of thing I mean: if Strange New Worlds can do it for the Gorn… what other alien races could see their more horrifying qualities ramped up? And could some of these be interesting for a future episode or series?
With all of the preamble out of the way, let’s take a look at five alien races that I think could have been terrifying!
Alien #1:
The Klingons

By the time Star Trek had updated the design of the Klingons and delved a bit deeper into their warrior culture, a decision had already been taken to make the Klingons friendly. But if you think about it… a race of incredibly strong, bloodthirsty warriors who are eager to die in battle could be genuinely terrifying with the right script.
However… when Discovery stepped back in time and set up its Klingon war arc in Season 1, we didn’t really get that. There were some tense moments and some neat action sequences, but part of me thinks that there have probably been too many storylines with Klingon heroes and protagonists for long-time Trekkies to take them seriously as a threat in the future.

If The Next Generation hadn’t gone down that route, though… there’s a ton of potential here. Imagine an episode set on a derelict ship where a lone Klingon warrior is slowly hunting down a Starfleet away team. Or a story set aboard a station like DS9 where a handful of Starfleet personnel are desperately trying to protect civilians from an onslaught of warriors who aren’t afraid to die in battle. The Klingons’ single-minded dedication to war and combat makes them frightening, and their physical strength when compared to (most) humans makes them truly dangerous opponents.
Unlike some other aliens we’re going to talk about, I very strongly doubt we’d ever get a Klingon-themed horror episode! It would be difficult to pull off after seeing hundreds of episodes with the likes of Worf, B’Elanna, Martok, Gowron, and so on, and I suspect the fan community wouldn’t really be on board with the idea, either. But I stand by my pick: with the right script, filmed in the right way, this warrior race could be absolutely terrifying.
Alien #2:
The Sheliak

Strange New Worlds took the Gorn – an alien race which had only appeared a couple of times in Star Trek – and turned them into a major antagonist. So… why not do something similar with the non-humanoid Sheliak? The Sheliak appeared in just one episode – and kind of similarly to the Gorn in Arena, they weren’t the only part of that story! In fact, only one individual was seen on screen, and even then, only for a few moments.
However, the Sheliak have a really interesting and unusual design, especially by Star Trek standards, and for a one-off alien race that hasn’t been so much as mentioned in more than thirty-five years… they’re pretty memorable. To me, anyway!

The Sheliak’s inhuman nature and incomprehensible language already make for an intimidating starting point, but their approach to other races – including humans – could really jump-start the fear factor. Viewing other races as inferior, and having no qualms whatsoever about wiping out whole settlements is a frightening idea – and if the Sheliak can back that up with technology, weapons, or perhaps some kind of weird alien goo, I think the stage is set for a genuinely frightening adversary.
Being somewhat of a blank slate, there’s a ton of room to expand on our knowledge of the Sheliak. They’re sentient life-forms, not “monsters,” but there’s still a ton of frightening potential in any intelligent non-human alien.
Alien #3:
The Founders/Changelings

A shape-shifting enemy that can – and already has – infiltrated Starfleet and the Federation? That seems like something with a lot of horror potential! Look at the classic horror picture The Thing as a great example of how something like this could work. An impostor living amongst a Starfleet crew, slowly picking them off, and the survivors losing their minds not knowing who to trust. A story like that is textbook horror.
Picard’s third season had a chance to do this, but the story there leaned more on the mystery and action side of things, rather than horror. There were some shocking moments, and the idea that anyone could, in theory, be a changeling did set up some tension for a time. But then the story went in a different direction towards the end, so that terrifying potential didn’t really amount to much, at least not in terms of horror.

One thing we’ve never really seen in DS9 or Picard is a Founder shape-shifting into some kind of truly monstrous and powerful form. If they can take the shape of birds, humanoids, or even a cloud of gas, there’s nothing stopping them from turning into a three-metre-tall eldritch horror with tentacles and needle-sharp teeth! Again, these abilities have been teased sometimes, but never really taken advantage of in a horror sense.
There are timeline questions, of course. A story set after the Dominion War, in a largely peaceful era, would struggle to justify including the Founders as a major antagonist like this. But, as in Picard, there could be a renegade faction or even an individual. In any case, Star Trek has done some cool things with shape-shifters – but really hasn’t even scratched the surface in terms of their horrifying possibilities!
Alien #4:
The Borg

The Borg are scary. They’re “space zombies,” as I wrote once, and part of what makes them so frightening is that every ally lost to assimilation becomes another enemy to fight. The Borg also embody the idea of a “fate worse than death;” losing one’s mind, being turned against one’s friends and allies, and continuing to exist in a kind of limbo state. But think about it… have any Borg episodes really fallen into the “horror” genre?
For years, I’ve wondered whether Star Trek should try a “Borg Invasion” television series – a show in which the Borg make a real push to assimilate the Federation and the Alpha Quadrant. Such a show, were it to ever exist, would undoubtedly benefit from leaning into a horror tone – at least some of the time. Ramping up the fear factor by showing that no main characters are safe, that the Borg are this unstoppable “force of nature,” only interested in assimilation… I think it could be exceptional if done well.

There have been some scary Borg moments over the years, and the faction’s aesthetic really leans into horror tropes. But since the introduction of the Borg Queen in First Contact, I kind of feel like the Borg lost part of what made them so special in the first place. If it were up to me, I’d create a retconned version of the Borg akin to their original appearances in Q Who and The Best of Both Worlds – interested in assimilation and technology, and completely unable to be reasoned with, talked down, or negotiated with. That, in my opinion, is a huge part of what made the Borg unique – and scary!
But even with a Queen, there’s still a lot more Star Trek could do to give us a Borg horror story – even if it was just a one-off episode, not a whole show. An episode with a tone like All Those Who Wander or Shuttle to Kenfori would work exceptionally well with the Borg as antagonists.
Alien #5:
The Terrans

If you know me, you’ll know that the Mirror Universe (and its Terran inhabitants) has never been my favourite part of Star Trek… and that’s putting it mildly! But I won’t deny the horror potential in the setting, which is all about murder, violence, and torture. Imagine an unsuspecting officer being transported there, totally unaware of what was happening, and being hunted down by an entire galaxy full of violent sociopaths!
In past Star Trek stories, the rare moments where a character has actually met their Mirror counterpart have been played humorously, but if you think about it, the idea of discovering that you essentially have an “evil twin” is another horror trope that the Mirror Universe could lean into. Being kidnapped by a Terran because your Terran counterpart is someone high up in the Imperial military would be absolutely terrifying.

Again, decades’ worth of pretty low-quality Mirror Universe stories – episodes which, intentionally or not, came across as being funny rather than thought-provoking or scary – definitely count against this idea! But a good enough script should be able to see the Terrans and their Mirror Universe as the terrifying antagonists that they could have been!
Plus, it would be nice to get a Mirror Universe story with genuine stakes and a fear factor, instead of hammy over-acting and one-dimensional characters. Maybe the Terrans wouldn’t be my first choice to write a horror story around, but I definitely think the setting could lend itself to something frightening.
So that’s it!

We’ve talked about a handful of Star Trek aliens that aren’t usually all that scary… but *could* have been!
I hope this was a bit of fun, and a little bit of a thought experiment. Star Trek is, as I said earlier, not a franchise that usually delves deeply into horror. That’s not to say it never happens, because it does, and it can work really well! But it’s just not a genre that the franchise’s writers typically like to play around in. At most, we’ll get a one-off horror-tinged story. But a feature film or season-long arc still seems a long way away.
I have a couple of other horror/Halloween ideas that I hope to get around to before the 31st, but I’ve been exceptionally busy over the past couple of weeks, so I’m not sure if I’ll manage to do everything in my writing pile. Might have to save one or two of those ideas for Halloween 2026! Still, I hope you’ll check back, because I daresay I’ll have more to say about Star Trek, sci-fi, horror, and the wide world of geeky entertainment before too long! See you… out there.
The Star Trek franchise can be streamed on Paramount+ in countries and territories where the platform is available, and most shows and films are also available on various on-demand platforms, as well as DVD/Blu-ray. The Star Trek franchise – including all properties, shows, and films discussed above – is the copyright of Skydance/Paramount. This article contains the thoughts and opinions of one person only and is not intended to cause any offence.

