Star Trek: The Next Generation Episode Re-Watch: Season 1, Episode 22: Skin of Evil

A Star Trek-themed spoiler warning.

Spoiler Warning: There are spoilers ahead for Star Trek: The Next Generation. Spoilers are also present for the following Star Trek productions: The Wrath of Khan, The Search for Spock, Deep Space Nine, Enterprise, Picard Season 3, and Star Trek Online.

This past weekend, I had the opportunity to meet Denise Crosby at a Star Trek convention here in the UK! So what better way to celebrate than by returning to what is arguably Tasha Yar’s most iconic episode: Skin of Evil?

I haven’t written up a full article on this year’s Destination Star Trek convention, by the way; much of what I said last year about the organisation, great accessibility, and so on still applies, and I didn’t really want to repeat myself. If you join me later in the year for my “year in review” piece, I daresay I’ll discuss Destination a bit more then. And if you want to see what I made of last year’s event, you can find out by clicking or tapping here!

For now, suffice to say that it was wonderful to meet Denise Crosby, share a fist-bump, and pose for a photo. And that meeting is what convinced me to return to this episode for the first time in… well, a while, I guess!

Still frame from a video clip of Denise Crosby at Destination Star Trek 2026
Denise Crosby faces off against “Armus” at a Star Trek convention in the UK.
Image: Destination Fan Events via Facebook

If you’re a Trekkie and a big fan of TNG, I daresay you already know the story of how Skin of Evil came about. In brief, Crosby became dissatisfied relatively early on, feeling that the character of Tasha Yar wasn’t being given much to do or getting much time on screen. As a result, she asked to leave the series while production on Season 1 was still ongoing; by January 1988, the script for what would become Skin of Evil had been drafted.

This is, in a very real sense, a landmark episode – not only for The Next Generation, but for Star Trek as a whole. We’d seen plenty of redshirts killed off before, and villains, too – but this was the first time that a *main* character had been killed (and stayed dead, so Spock doesn’t count!). Not only was that new for Star Trek, but it was a relative rarity in prime-time television at the time, too.

Still frame from Star Trek TNG 1x22 showing Tasha's death
Tasha’s death was a first for Star Trek.

I’d argue that Tasha’s death set the stage for Worf to grow into the character we’ve come to know and love. Worf took over the security and tactical roles that had initially been hers; it’s hard to envision Worf’s subsequent development across both The Next Generation and Deep Space Nine if he’d remained a roving presence on the Enterprise-D. Tying him down to a role that both suited his skillset and – arguably – kept him in a pretty narrow lane defined his character. And as Worf is the character with the most appearances in Star Trek (285, according to Memory Alpha), that’s kind of a big deal! In that sense, Skin of Evil arguably did more for Worf than for any other character – including Tasha Yar.

For her part, I think it’s fair to say that Denise Crosby quickly came to recognise that leaving the show was a mistake. As The Next Generation “grew the beard” and went from strength to strength, missing out on that must’ve stung. Crosby would return to the series in guest-starring roles as an alternate timeline’s version of Tasha Yar, and then as Yar’s half-Romulan daughter, Sela, for a pretty successful story arc. But Tasha Yar is not as big a character as she could’ve been, and I’ve always felt that there’s some regret from Denise Crosby because of that. Crosby has remained involved with the Star Trek fan community, though – not only making convention appearances, like the one I attended, but also producing the documentary Trekkies and its sequel, as well as appearing in the video game Star Trek Online.

Screenshot from Star Trek Online showing Sela
Denise Crosby has returned to Star Trek on multiple occasions since Tasha was killed off.
Pictured: Star Trek Online

I first came to The Next Generation (and Star Trek as a whole) during the show’s second season, so it was only when episodes of Season 1 were repeated that I would’ve encountered Skin of Evil – and Tasha Yar as a character. That being said, it must’ve been sometime in the early ’90s, because I don’t have a particularly strong memory of watching Season 1 and thinking “wait, who’s that character standing at Worf’s post?” So I think my younger self just kind of rolled with it! I also couldn’t tell you exactly when I first watched Skin of Evil or what I made of it… though I do seem to have a fragment of a memory, wondering why – with all the 24th Century medical technology present in the show – Tasha’s life couldn’t be saved and Dr Crusher simply pronounced her dead.

We’ll get into all of that in a minute, though, because I definitely have some thoughts about the way this episode implemented its main storyline!

One thing I really wasn’t sure of, all these years later, is whether – or to what extent – Tasha’s funeral would still hit those emotional notes. Knowing what’s coming in a story can rob it of its impact, and having seen Skin of Evil more times than I can remember… well, I just didn’t know how I’d feel, I guess. Tasha’s death on Vagra II was expected on a re-watch, naturally, and the shock of the moment wasn’t there. But in her funeral scene? I still teared up.

Still frame from Star Trek TNG 1x22 showing Tasha's hologram at her funeral
Tasha at her own funeral.

On the technical side of things, I’d forgotten just how great Skin of Evil’s musical score is. As the ship races to Vagra II we get a tense, tension-building piece of music. On the planet, and in scenes with Armus, the music conveys a very real sense of danger. And finally, at Tasha’s funeral, the music changes again to take on an emotional, almost bittersweet tone as Picard and the crew listen to her final message. Ron Jones, the show’s regular composer for Seasons 1-4, wrote the episode’s score.

This is my personal bias coming through, but I’ve always liked what The Next Generation did with indoor sound stages – especially in the first season. Some of these settings feel much closer in visual terms to planets and locales from The Original Series than even to places we’d encounter just a couple of seasons later. For me, there’s a real charm to the way Vagra II (and similar places) are presented; it’s something Star Trek literally hasn’t done for decades. And while it may be less “realistic” in an objective sense, with fairly plain, flat terrain, scattered rocks, and a clear stage backdrop that, in this case, was an incredibly basic colour gradient… I really like the way these places look. It’s a limitation of both budget and technology, as well as a product of its time – and I think if one of Star Trek’s modern shows saw an away team land on a planet that looked like Vagra II, we’d criticise it! But… I just find it charming in episodes like this one.

Still frame from Star Trek TNG 1x22 showing the Enterprise-D bridge set
I like this overhead shot.

Skin of Evil also had some creative camera shots. The close-up on Picard, at the end of the funeral, lingered in such a way as to convey his emotional state, even as he didn’t really show a lot of emotion on his face. There was a great overhead shot of the bridge that we’d occasionally see in the show’s first season but very rarely thereafter. And some of the shots of Armus (and Riker submerged in the Armus goop) were also well-framed.

The wreck of the shuttle looked great on the surface of Vagra II. The damaged nacelles and the back section of the shuttle made for a striking visual effect when we first saw them – comparable, perhaps, to earlier Star Trek episodes like The Galileo Seven. The damaged shuttle interior, where Troi and the injured Ben spent most of the episode, was also brought to life well, and the red emergency lighting really set the tone.

till frame from Star Trek TNG 1x22 showing the wrecked shuttle
The shuttle crash site.

We should also talk about the difficulties the team had in creating Armus, since we’re talking about sets and such.

The costume used to depict Armus’ humanoid form wasn’t compatible with the liquid that enveloped it, and the glue used to hold parts of it together repeatedly came unstuck during filming. The viscous liquid – a mixture of printer’s ink and a thickening agent – was infamously unpleasant to work with, not least for Jonathan Frakes, who performed his own stunts in the episode, including being submerged in the stuff.

It sounds like working on that side of the episode was more of a challenge than the crew expected, but I think the finished product works about as well as it could! I don’t think anyone’s out there hailing Armus as one of Star Trek’s best or most iconic villains – which is a shame, given his role in killing off a main character – but the way he comes across on screen, dripping, jet black, oozing, and unpleasant… it made for a suitably menacing and intimidating effect. Seeing Armus rise taller than Riker – the tallest of the main cast – hammered that home.

till frame from Star Trek TNG 1x22 showing Armus
Armus.

Armus is, though, a pretty one-note villain, if you think about it. Partly that’s by design: if he’s an entity composed *entirely* of an entire alien race’s worst and most negative qualities, well… there isn’t a lot of room for nuance, I guess. And partly, it should be said, it’s because this single forty-five-minute episode had other things to do. Worf had to accept his new role and play a major part on the bridge when Picard, Riker, and Data were all away. We had a sequence in Sickbay trying to save Tasha’s life. And then the funeral, at the end of the episode, needed sufficient time to hit those emotional notes. There wasn’t more time, sadly, for Armus to be much more than he was.

That also means that the resolution to the episode’s core problem – the need to save the shuttle crew – felt quite abrupt. After Picard and Troi hit on the idea of basically making Armus as upset as possible to weaken his forcefield… that was it. We got a short conversation as Picard pushed his buttons, leading to a pretty stereotypical “roar of anger,” before the away team were all beamed away to safety. A bit anticlimactic, perhaps, given what Armus had done earlier in the story.

Behind-the-scenes still from Star Trek TNG 1x22 showing production crew on set
Members of the production crew on the set of Skin of Evil.

In some ways, Armus feels like a different take on a familiar character from TNG’s first season: Q. They exhibit some of the same traits – a need to be amused or to have attention focused on them, trickster-like, teasing qualities, and powers that go far beyond what Starfleet in this era was able to counter. But while Q, even in his first appearances, had both a curiosity about humans and even, dare I suggest, a helpful streak… Armus is purely malevolent.

I liked Troi’s line about pity; how this creature, powerful and deadly though it could be, was still a tragic and sad figure. Armus represents one of the oldest warnings about immortality, in one sense: how one would feel after aeons alone, trapped with no one to talk to or nothing to do. That isn’t meant to justify or excuse his behaviour, but it does go some way to giving it an explanation or at least some context. To choose a real-world parallel: Armus is akin to the criminal who comes from a troubled past. Their past doesn’t give them free rein to do the bad things they’ve done, but it can go some way to explaining why those things happened, where they came from, and even why we should pity, rather than *hate*, someone in that position.

till frame from Star Trek TNG 1x22 showing Troi
Troi.

Troi was arguably Skin of Evil’s real star. This episode must be one of Marina Sirtis’ best and most challenging performances in the role, having not only to display very strong emotions, but doing so with no other physical performer to bounce them off. Every conversation Troi has with Armus, unlike those of the rest of the away team, takes place inside the shuttle with only Armus’ voice. It’s a tricky acting challenge, but Sirtis rose to the occasion wonderfully.

Troi was also the character who figured out how to beat Armus, laying the groundwork for the resolution to this storyline. It might’ve been possible, based on what we saw of their earlier conversations, for Troi to have single-handedly defeated Armus without Picard’s intervention; that’s a fun little “what-if” idea, I guess. But again, this was a good episode for both character and performer, and Troi really excelled – despite spending most of the episode trapped in a wrecked shuttle, barely moving.

till frame from Star Trek TNG 1x22 showing Picard with Troi in the shuttle
This was a good episode for Troi.

At this point in The Next Generation’s run, we had seen Picard on a handful of away missions, but we’re also aware that he’s a very different kind of captain from Kirk – taking a much more hands-off approach, with Riker usually leading the charge. So to see Picard volunteer to beam down to the planet himself was something a bit different, and I think it emphasised the severity of the situation. As I said above, Picard’s ultimate role *might* not have been totally necessary, but as the captain, it makes sense for him to play a leading role in this kind of story.

Picard’s dedication to helping his crew – the away team, Riker, Tasha, and the survivors of the shuttle crash – was on full display, and it’s one of the best early-season indications of this, in my opinion. We also get to see Picard having to wrangle with the emotional toll of losing someone under his command, someone he personally recruited, as well as someone he’d become friends with, while also having to remain in control of his emotions and guide the rest of the crew. Tasha’s death was cruel, and they were all suffering – but there was still a mission at hand and two injured crewmates to rescue. Picard had to be the one to tell them to keep their emotions in check long enough to help the shuttle crew, and that can’t have been easy.

till frame from Star Trek TNG 1x22 showing Picard in the Briefing Lounge
Picard in the Briefing Room.

I mentioned Worf above, and for me, Skin of Evil feels like *the* inflection point for his character; the moment the version of Worf we’re most familiar with came into being. With Tasha’s death, Worf is given her roles at tactical and security by Picard, and we see a flicker of emotion on his face at that moment as he absorbs both the loss of a friend and the responsibility of assuming her dual roles aboard the ship. Worf instantly puts his own stamp on things, though – declining to join the away team, despite clearly wanting to avenge Tasha’s loss, because he believed his skills were better-utilised on the bridge.

Worf feels like a natural fit for the security and tactical roles – though that’s admittedly with the bias of hindsight! As I revisit Skin of Evil, though, I can’t help but wonder what might’ve been – what other role or roles would Worf have found aboard the Enterprise-D had Tasha remained a part of the series? It’s another of those interesting “what-ifs,” eh?

till frame from Star Trek TNG 1x22 showing Worf and Tasha Yar
Worf and Tasha together at the beginning of the episode.

I was also reminded of how, even a full season into the show’s run, TNG lacked a chief engineer! Geordi wouldn’t take over that role until Season 2, and Season 1 showed off a succession of one-off characters in the engineering role. In this case, we meet (briefly) Leland T. Lynch, who was responsible for recalibrating the ship’s dilithium crystals at the start of the story. Lynch was a very minor part of the episode, and didn’t return after Skin of Evil, but he’s just a reminder, really, of how – despite having a successful formula from The Original Series to adapt – The Next Generation was still finding its feet, even a full season into its run. As with Worf above, we’ve come to see Geordi as inseparable from his role in engineering… but that wasn’t where he started.

Although Engineer Lynch’s work on the dilithium crystals kind of feels like padding to stretch out the episode’s runtime a little, it did lead to one cool visual moment: seeing the Enterprise-D in flight but without its nacelles illuminated. This made for a fun and different look, albeit just for a moment, and the need to reach Vagra II added a little tension to those opening moments after the shuttle crash, too.

till frame from Star Trek TNG 1x22 showing Leland T Lynch
It’s Leland T. Lynch!

So let’s talk Tasha.

Skin of Evil is remembered not for Armus, nor Worf’s new role, nor even Troi’s struggle against Armus, but because it’s the episode where Tasha Yar was killed off. Although Star Trek had killed off Spock a mere six years earlier, that doesn’t really count because the next film brought him back to life again! So this was Star Trek’s first real encounter with death, if you think about it. Combine Tasha’s death here with Dr Crusher’s departure at the start of Season 2 (something caused by behind-the-scenes shenanigans), and it definitely felt like TNG was going through a shake-up.

This is something that Star Trek still doesn’t really do very often. If you remember my reviews of Discovery and Picard in recent years, you might remember me saying words to the effect of characters seeming to have “plot armour” even in seemingly impossible situations! And that’s because, to be blunt, I don’t think the franchise has *ever* done death particularly well. Spock’s was emotional and impactful… but was undone in the very next story. Jadzia’s, which came a decade after Skin of Evil, is arguably the most impactful… but others, like Kirk’s or Tucker’s, have proven incredibly controversial. And don’t get me started on redshirts and “glorified redshirts!”

till frame from Star Trek TNG 1x22 showing Tasha on a bio-bed
Tasha Yar was Star Trek’s first major death.

So this moment… it still matters to Star Trek, even as we close in on Skin of Evil’s fortieth anniversary. This is the moment where main characters could no longer be considered safe, where someone other than a redshirt went on an away mission… and didn’t come back. A character fans had gotten to know over more than twenty episodes, who had relationships with practically everyone else on the Enterprise-D just… straight-up died. And the show made a creditable effort to celebrate Tasha’s life and legacy in a funeral scene that still hits hard all these years later.

The contrast between the dim, desolate surface of Vagra II and Tasha’s funeral – in a sunlit, grassy meadow – is stark, and the visual impact of the two sequences is incredibly striking. At first, the moment felt less funereal than Spock’s had done aboard Kirk’s Enterprise, but this memorial service was for a different character, and a different *kind* of character, too. In my head canon, Tasha chose such a bright, sunlit, pastoral setting because it represented everything she got away from when she escaped to join Starfleet. And there’s something about the bright blue sky, white clouds, and natural grassland that feels, well… heavenly, at least if you buy into western or American depictions of the afterlife.

till frame from Star Trek TNG 1x22 showing the funeral and the holodeck doors
The characters gather for Tasha’s funeral.

Skin of Evil needed this epilogue. If Tasha was going to be killed off – and not exit the show by some other means – then her death needed more than just expiring on a bio-bed in Sickbay. The funeral, and particularly Tasha’s own address to the gathered characters, was her swansong; the end of her time on the show. It mattered to those involved – the cast as well as the characters they played – but also to us as the audience. The funeral underlines that there is no technobabble solution – Tasha isn’t coming back and there will be no last-second reprieve. It allows us to bid a fond farewell to the Enterprise-D’s first tactical officer, and to draw somewhat of a line under the first iteration of the show’s principal cast.

Tasha Yar was always an enjoyable character. Her tragic backstory informed why she wanted to join Starfleet, and why she had the tactical and combat skills that she possessed, but it didn’t define her. She may not have been front-and-centre across Season 1, but just like most of the rest of the main characters, she had her moments, made connections with her shipmates, and took part in some iconic moments and storylines. Her loss in Skin of Evil would go on to define – and, I would argue, refine – The Next Generation going into Season 2.

till frame from Star Trek TNG 1x22 showing Tasha on the bridge
Tasha at her post on the bridge.

And, of course, Tasha would be back! Yesterday’s Enterprise introduced an alternate timeline version, she returned again in All Good Things right at the end of the show’s run, and her daughter – Sela – was an important character, too. Tasha even appeared, albeit only briefly, in Picard’s third season, proving that her legacy and importance lived on well past the events of this one episode. She would prove important to Data in particular (thanks in no small part to their… y’know… *encounter* in the episode The Naked Now). And all these years later, we’re still talking about Tasha Yar and her place in the series.

So I think that’s all for now.

Thanks for joining me on this re-watch. It was fun to revisit Skin of Evil, even though I wouldn’t necessarily consider it a personal favourite episode, or anything! Skin of Evil is more so an inflection point; a key moment in the history of The Next Generation, moving one character aside and arguably making room for others to step up. Slimming down what was arguably a slightly overladen cast probably helped the series going into the next part of its run, and for Worf in particular – an incredibly important character in all of Star Trek’s history – this moment cleared a pathway for him to become the character we know and love.

Behind-the-scenes photo from Star Trek TNG 1x22 showing Denise Crosby
Denise Crosby during a break in production.

If you missed them, earlier this year I wrote up re-watches of The First Duty and The Royale, from Seasons 5 and 2 respectively, and I’d love to get around to more episode re-watches soon, too. I’ve also been reviewing Season 4 of Strange New Worlds, I reviewed Season 1 of Starfleet Academy, and the video game Across The Unknown. I hope you’ll check out some of those if you have the time!

Star Trek’s sixtieth anniversary is upon us, and it was wonderful to be able to celebrate that milestone at a convention. Meeting Denise Crosby was a wonderful experience, and it’s what prompted me to step back to Skin of Evil and write this piece. I hope this has been interesting, and I hope it wasn’t too controversial a pick for a Tasha Yar episode to revisit!

Thanks for joining me, and as always… Live Long and Prosper, friends!


Star Trek: The Next Generation is available to stream now on Paramount+ in countries and territories where the service is available, and is also available to buy on DVD/Blu-ray. The Star Trek franchise – including The Next Generation and all other properties 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.

Star Trek’s Scariest Alien Monsters!

A spoiler warning graphic.

Spoiler Warning: There are spoilers ahead for the following Star Trek productions: The Original Series Season 1, The Voyage Home, The Next Generation Season 1, Deep Space Nine, Voyager, Picard Season 3, and Strange New Worlds Season 1.

It’s Spooktober – the spookiest month of the year! So I thought we could have a bit of fun and talk about some of the scariest aliens and villains that the Star Trek franchise has brought to screen.

Star Trek isn’t a franchise that’s well-known for being all that frightening. I don’t think that’s a controversial statement at all – in fact, I’d wager that most TV viewers would consider it pretty tame, especially when thinking about the horror genre and alien monsters! But that doesn’t mean Star Trek is never scary. There are some wonderfully atmospheric episodes and stories scattered throughout the franchise’s fifty-eight-year history that have some of those more frightening elements.

Still frame from Star Trek: Picard Season 3 (2023) showing a Borg cube.

Today, rather than talking about individual stories or episodes, what I’d like to do is pick out some of the franchise’s scariest aliens, monsters, and villains – and talk about why they work so well, why they’re so intimidating, and perhaps even just the potential they have to be frightening or scary in future stories.

My usual caveat applies: everything we’re going to talk about is the entirely subjective opinion of one person only. If I miss something you think is blindingly obvious or if I include a “scary” alien that you think isn’t frightening in the least… that’s okay! There’s plenty of room in the Star Trek fan community for disagreement and differences of opinion.

With that out of the way, let’s talk about some of Star Trek’s scariest aliens and villains!

Number 1:
Q and the Q Continuum

Still frame from Star Trek: Picard Season 2 (2022) showing Q.

The Q are on the list less for their out-and-out fear factor and more for their potential. I don’t think there have been many terrifying or bone-chilling Q appearances – though I will entertain the argument that Q’s penchant for randomness can have an unsettling or unnerving quality. Things like conjuring up aliens in Napoleonic uniforms or a post-atomic courtroom would be incredibly frightening in real life, even if they’re portrayed more as chaotic and wacky when we see them unfold on screen.

The Q Continuum’s real fear factor comes from their apparently unlimited power. No other alien race in Star Trek is as powerful as the Q, and they could quite literally wipe out humanity, the Federation, or even the entire galaxy with a wave of the hand. Although we always see Q as humanoid, their true form is a mystery, and their power seems to be without limit – and without a reliance on technology. No war against the Q seems possible, and if they ever chose to move against the Federation (which they could do for reasons beyond our comprehension, or to prevent some kind of conflict in the far future that we have no inkling of right now) they could be far more destructive than even the Borg.

Number 2:
The Gorn
(As they appear in Strange New Worlds)

Still frame from Star Trek: Strange New Worlds Season 1 (2022) showing a juvenile Gorn.

The Gorn are one of Star Trek’s oldest alien races, appearing in the first season of The Original Series. But after that initial appearance and a few scattered mentions through The Next Generation era, they didn’t show up on screen again until Enterprise. That depiction wasn’t great, in my view – it relied too heavily on CGI that didn’t look great at the time and hasn’t aged well. But the return of the Gorn in Strange New Worlds has been a triumph.

After several episodes built up the terror of Gorn raids on the Federation, it was the episode All Those Who Wander that really showed us what this new depiction of the Gorn can do. Strange New Worlds’ writers unleashed the Gorn in an episode that, more than any other in the franchise, leans into the horror genre. The Gorn are depicted almost like the Xenomorphs from the Alien film series, possessing strength and stealth abilities that left the away team cornered.

Number 3:
The Founders/Changelings

Still frame from Star Trek: Deep Space Nine showing a changeling in their gelatinous state.

Maybe this one is a little controversial, but after the way Changelings were depicted in Picard’s third season I think we have a pretty good case to include them as a frightening bunch! The idea that shape-shifters could infiltrate Starfleet and the Federation was addressed in a fantastic Deep Space Nine two-parter: Homefront and Paradise Lost. These episodes took more of a political thriller/drama approach to the topic, but the core idea is a deeply unsettling one.

With the Dominion playing a growing role in Deep Space Nine, the idea of Changeling infiltrators was scaled back and only used sparingly – probably because it’s not an easy story to write or pull off successfully. But Picard Season 3 brought the idea back in a creative way, showing how deadly Changelings could be and how a Changeling plot could be an existential threat to the Federation.

Number 4:
The M-113 Creature
(a.k.a. The Salt Vampire)

Still frame from Star Trek: The Original Series Season 1 (1966) showing the M-113 Creature.

The first ever alien to appear on The Original Series remains one of the franchise’s most frightening! The episode The Man Trap kick-started the Star Trek franchise back in 1966, and the Salt Vampire was the first alien that audiences saw Kirk and the crew wrangling with. As discussed above with the Changelings, the alien’s ability to change shape and blend in added to its fear factor – but moreover, its true appearance is pretty unsettling even today. There’s something to be said for those old rubber suits, eh?

The Salt Vampire is a sci-fi take on ancient legends and creatures from folklore, and that gives it a uniquely frightening feel. Preying on some of these old primordial fears lends the creature a genuinely intimidating vibe, and its grotesque appearance just adds to that. The Salt Vampire is, however, a tragic figure, as it appears to be the last of its kind; more akin to an animal acting out of instinct than a truly nefarious villain.

Number 5:
The Borg

Still frame from Star Trek: First Contact (1996) showing a Borg drone.

In my essay The Borg: Space Zombies, I go into a lot more detail on this topic, but the condensed version is this: the Borg fill a similar role to zombies in horror fiction, while also picking up on both Cold War-era fears of brainwashing and concerns about technology getting out of control. The idea of assimilation is incredibly clever, as it turns every ally the heroes lose into a new enemy to fight, making the Borg grow in strength at the exact same rate as Starfleet weakens.

The idea of being assimilated and losing one’s mind and identity is arguably a fate worse than death – and we’ve got several examples in Star Trek of ex-Borg wrangling with the consequences of what the Collective forced them to do. I would note that the Borg’s fear factor has declined over the years, particularly during the latter part of Voyager’s run. Seeing Starfleet triumph over the same adversary again and again – no matter how intimidating it may be on paper – does start to take the shine off things.

Number 6:
Armus

Still frame from Star Trek: The Next Generation Season 1 showing Armus.

Armus has the distinction of being the first alien monster to kill a main character on a Star Trek TV series. There were many ways The Next Generation’s writers could have written out Tasha Yar when Denise Crosby opted to quit the show, but killing her off was a bold move. And doing so in such a brutal way, with Armus not even batting an eye at her death… it was quite something to see.

If you have the DVD or Blu-ray of The Next Generation it’s worth watching the actors and producers talk about working on the episode Skin of Evil, because creating Armus and performing around the inky-black oil slick was incredibly difficult for everyone involved to say the least! Jonathan Frakes in particular had a very tough time with Riker’s scene when he was pulled under the surface. Armus is a scary-looking villain, and also one that had a profound, long-lasting impact on The Next Generation.

Number 7:
The “Whale Probe”

Still frame from Star Trek IV: The Voyage Home (1986) showing the Whale Probe.

Although the tone of The Voyage Home is pretty light-hearted and comedic, the so-called “whale probe” that kicks off the plot is an incredibly terrifying adversary, when you think about it. The probe disables Starfleet vessels with incredible ease, and is resistant to weapons and all attempts at communication. The people of Earth have no idea what it wants, what its purpose is, or how to reason with it.

This monolith simply arrives unannounced, doesn’t declare its intentions, and seems to wreak havoc on Earth and Starfleet. That’s a pretty scary concept, in my view, as it could’ve gone pretty badly for everyone involved if Kirk and the crew hadn’t intervened!

Number 8:
The Pah-Wraiths

Still frame from Star Trek: Deep Space Nine Season 6 showing Jake Sisko possessed by a Pah-Wraith.

As with Armus, there’s something distinctly “evil” about the non-corporeal Pah-Wraiths. The way they’re presented in multiple Deep Space Nine episodes, where they’re deeply entwined with Bajoran religion, makes them out to be akin to demons or dark spirits – and we even see them “possess” several different characters. Their banishment to Bajor’s fire caves also ties into this demonic analogy.

In later seasons, Gul Dukat gets involved with the Pah-Wraiths, leading a cult on Empok Nor that’s genuinely unsettling in its depiction. The Pah-Wraiths have magical books, the power to turn people blind, and the desire to conquer the Prophets’ domain in the Wormhole; a truly frightening group!

Number 9:
The Conspiracy Parasite-Aliens

Still frame from Star Trek: The Next Generation Season 1 showing a parasite-alien.

The end of The Next Generation’s first season introduced a race of parasitic aliens that infiltrated Starfleet. Allegedly, the parasite-aliens were supposed to be connected to the Borg in some way, but this angle was later dropped. Still, they’re more than frightening enough on their own terms, and the idea that Picard and the crew wouldn’t be able to tell who was infected and who to trust made for an entertaining story.

Here in the UK, one scene toward the end of Conspiracy was cut from the original broadcast because of how gruesome it was! You know the one: where the “mother” parasite is killed and violently explodes. There’s something just unsettling about earwig-like alien parasites… just like the Ceti Alpha eel from The Wrath of Khan. Star Trek hasn’t revisited the parasite idea for a long time – maybe it could make for a fun and horrifying future episode?

Number 10:
The Krenim

Still frame from Star Trek: Voyager Season 4 showing Annorax.

The Krenim appeared in the Voyager two-parter Year of Hell, using their time-manipulation technology as a weapon. Repeated Krenim attacks against the USS Voyager left the ship in ruins, running on fumes, and many members of the crew dead or maimed. The captain of the Krenim time-ship, Annorax, was Khan-like in his single-minded obsession with restoring the Krenim colony that housed his wife and family, making him a frightening adversary.

Year of Hell is a pretty shocking episode, particularly in its second half. Seeing Voyager badly damaged, with whole parts of the ship uninhabitable, really hammers home how dangerous the Krenim and Annorax are as villains, and for a time their technology really does seem to be more than a match for Janeway and the crew.

So that’s it!

Still frame from Star Trek: The Original Series (1966) showing a Gorn.

We’ve picked out what I consider to be a selection of Star Trek’s most frightening aliens, monsters, and villains to celebrate the spooky season.

There are plenty of others that we could’ve included – either for their fully-blown fear factor or for their potential to do serious harm to our Starfleet heroes. And there are quite a few Star Trek episodes – a surprising number, really – that either lean fully into the horror genre or that have jump-scares or other frightening or unsettling moments. Last year, I put together a list of a few of them, which you can check out by clicking or tapping here if you’re interested!

So I hope this has been a bit of fun! I hope you’re having a fun and spooky October – and stay tuned, because I have a couple of other Halloween-themed ideas that may (or may not, time depending) make their way onto the website before the 31st. Don’t have nightmares!


Most of the films and episodes discussed above are available to stream on Paramount+ in countries and territories where the platform is available. They’re also available for purchase on DVD, Blu-ray, and video-on-demand. The Star Trek franchise – including all films, episodes, and other properties discussed above – is the copyright of Paramount Global. This article contains the thoughts and opinions of one person only and is not intended to cause any offence.