Star Trek’s Best Antagonistic Species

We have hacked and slashed our way through the worst enemy species of Star Trek and stepped carefully through the most mediocre ones. Now, we finally get our reward* because Star Trek does have a few species that make for great villains! You’ve probably guessed most of today’s entries, but what order will they be in? Why are some better than others, and who’s the very best? Obviously, the only way to answer that is with a countdown until we reach that most coveted of titles: Aliens Oren Thinks Are the Best Bad Guys. Make it so!

7. Species 8472

These CGI baddies only appear in a total of four episodes,* and unlike some other aliens we’ve looked at, they aren’t built up in advance. Their presence in the show is so small that I almost discounted them from the list entirely. But in spite of only showing up a handful of times, Species 8472 has left an outsized impression with both Voyager fans and the larger Star Trek community. 

Part of that impression definitely comes from 8472’s look. Star Trek aliens are well known for being limited by human actors, but by Voyager’s fourth season, CGI technology had advanced enough to try something different. 8472 easily stands out from other Trek species, most notably because of their tripedal locomotion. These effects still hold up pretty well today, and they were spectacular in 1997. 

Let’s not kid around though: the main reason we remember 8472 is that their big introduction has them kicking the Borg’s ass. Other than god beings like Q, the Borg had been Star Trek’s most powerful species for years, so anyone who could beat them was automatically a force to be reckoned with. Granted, 8472 clearly cribs from the Borg handbook, assimilating with living infestation rather than nanites, but we can let that slide. 

8472’s mysterious nature also helps quite a bit. We know so little about them that they could be up to anything! Our heroes only know this new species is hostile thanks to Kes making brief telepathic contact with one and the fact that 8472 ships keep attacking them. Even the name Species 8472 is a Borg designation, and we never find out what they call themselves. Between their cool looks, threatening mystique, and undeniable power, 8472 could have easily become Voyager’s new big bad. 

So… why didn’t that happen? Partly, it’s because 8472’s first episode already has Voyager’s holographic Doctor whipping up a countermeasure to keep the new enemy at bay. That significantly reduces 8472’s threat level. But I suspect the more significant reason is production costs. These days, CGI is seen as a cheaper alternative to practical effects, often exploitatively so, but I doubt that was the case during Voyager’s initial run. Very few other aliens get the CGI treatment, certainly not anyone we see more than once. 

Whether my speculation is correct or not, 8472’s final appearance has them declare that the whole conflict with Voyager was a misunderstanding and they were totally friendly.* This effectively ends them as a threat, a tragically short run for a species with so much potential. Fortunately, they do a lot with the time they have.     

6. Klingons

It may be a surprise that the Klingons aren’t near or at the top of this list, but I promise there’s a reason! You can all put away your bat’leths and painsticks. What makes the Klingons difficult to judge is they’ve been altered and reimagined more often than any other Trek species, with a long list of writers and showrunners looking to leave their mark. 

In The Original Series, the most you can say about the Klingons is they’re definitely in the show. They’re sinister and sneaky, but not exceptionally so. They have little in the way of motivation or complexity. Defeating them is often comical rather than serious. The best the Klingons ever get is one episode where they have to team up with Starfleet against a common foe. Even then, they don’t have much substance other than being evil for the heck of it. There’s also a lot of blackface among early Klingons, so that’s not great.

In The Next Generation, the Klingons have become allies of the Federation, which is genuinely cool and expresses Star Trek’s message of peaceful coexistence. This is also where Klingons get their famous forehead ridge and strict code of honor. That’s more development than they had in TOS, but it’s also pretty one-note, to the point that “honorable Klingon” feels more like a stereotype than a cultural marker. 

Fortunately, TNG eventually developed the Klingon Empire away from this shallow depiction, mainly by delving into its internal politics. We learn that while the empire’s leaders talk a big honor game, they are really just as concerned with power as any other group of leaders. That’s two whole dimensions, not bad at all. 

Deep Space Nine continues this trend, even going into depth about the difficulty of staying at peace with such a militaristic society. The Klingons start as allies, become enemies, and switch back to allies as the political situation changes. We also get a lot of great Klingon characters like Martok and Gowron, in addition to the stalwart Worf. 

This depiction would probably be enough to move the Klingons several spots higher on the list, but then along comes Discovery’s first season. While the pre-show hype promised that the new Klingons would be complex and nuanced, they’re actually worse than in TOS. They’re still evil for evil’s sake, but now they’re super grimdark about it, gleefully torturing their prisoners to death, among other excesses. They also can’t properly enunciate anymore, for some reason. 

Discovery’s Klingons were so badly received that other than Worf in Picard’s third season, we haven’t seen any live action Klingons since. With luck, we’ll all agree to pretend that this version never existed. 

5. The 10-C

Species 8472 showed us what could be accomplished by moving beyond the humanoid requirements of Star Trek aliens, but it took another 25 years for that concept to fully mature. I’m of course talking about Unknown Species 10-C, the main antagonists for Discovery’s fourth season. These guys are basically Star Trek’s answer to Cthulhu, and I am all in. 

Like in any good cosmic horror, we don’t first encounter the 10-C directly. Instead, an artificial anomaly starts tearing through the Milky Way, gobbling up any ships, stations, and even planets in its way. At first, the characters naturally conclude that they’re under attack, but that isn’t the case. Instead, the anomaly is actually a tool for gathering resources. The fact that it’s devastating the galaxy is just a side effect. 

This is cosmic horror at its finest. The 10-C aren’t destroying the Federation out of malice; they’re not even doing it intentionally. They just don’t recognize the Federation as something they need to step around while planning their harvest. Oh, and the 10-C are from outside the Milky Way, living in an artificially created pocket of space. So cool. 

Once our heroes actually go looking for the 10-C, Discovery slowly doles out tidbits in the form of ruins and millennia-old skeletons. This shows that the 10-C are massive and utterly inhuman, but doesn’t dispel their mystique like it would if we saw a live one in the flesh. Downright spooky! 

Just as impressive as the 10-C themselves is the moral conflict around them. Both the Federation and the main characters are divided: Should they attempt diplomacy, or should they strike before the 10-C notice them while they still have the element of surprise? Diplomacy eventually wins out, and it’s the first time Discovery goes beyond talking about the importance of “Federation values” and really engages with what those values are. 

Once the characters decide to attempt communication, they have to figure out how to do that. It’s another sequence that really emphasizes Star Trek’s core message of avoiding violence whenever possible, even if the solution comes a bit too easily. This is also where the 10-C stumble as villains, because the explanation for why they were indiscriminately churning up the galaxy is that they didn’t realize any of the life there was intelligent. Somehow the spaceships weren’t a clue. It’s possible they could be lying, but they acquiesce to the Federation’s request too quickly for them to be in any way malicious. 

Despite this weakness, the 10-C are a great Star Trek antagonist and the only major bad guy where talking is the solution. This puts a unique Trek twist on venerable cosmic horror tropes, which is the best possible outcome when introducing a new kind of enemy to the franchise. 

4. Romulans

Just like their Klingon counterparts, the Romulans have been around since the beginning, though they don’t have nearly as much screen time. In fact, we only encounter the Romulans twice in TOS and a further handful of times scattered across TNG and DS9. 

Fortunately for the Romulans, what they lack in quantity, they make up for in quality. These are the guys to call if you want someone to play mind games with Kirk or Picard, and I can’t think of a major Romulan appearance that I would categorize as subpar.* In TOS, they engage the Enterprise in a tense game of space-submarine warfare. Then, they nearly capture the Enterprise in a contest of spy vs spy. Both times, the stories focus on a Romulan leader capable of matching wits with our heroes, and in a shockingly progressive move for the 60s, one of them is a woman! 

Fast forward to TNG, and the Romulans employ a similar but even more elaborate playbook. They nearly lure the Enterprise into starting a war on terms favorable to Romulus, which requires Picard to get pretty sneaky in his own right. Later, the Romulans engineer a civil war in the Klingon Empire and hatch a plan to conquer the planet Vulcan. That last one isn’t as well thought out, as it assumes a few thousand soldiers will be enough to occupy an entire planet, but Star Trek has never been great at military logistics. 

Deep Space Nine primarily uses the Romulans as one of the major Dominion War players. In fact, getting Romulus into the war makes for one of DS9’s greatest episodes, as Sisko wrestles with wartime ethics and Garak gets his spy game on. It really helps that despite the recurring antagonism, there’s very little direct conflict between Starfleet and Romulan warships. The Romulan Warbird certainly looks intimidating, and the shows spend years teasing us about how much damage they’d do in an open confrontation. 

This helps increase the Romulans’ threat level, but the real contributor is their cloaking technology. Other species can also cloak, most notably the Klingons, but the Romulans are masters of it. It pairs well with their strategy of luring the enemy into a mistake, since the cloak means they can always appear to take advantage of an exposed opponent. 

The Romulans’ main weakness is that they get little development beyond being fearsome opponents. Their culture is largely an enigma, even after we spend a two-parter on Romulus itself. There’s an interesting connection to the Vulcans, but the nature of that connection is only tangentially explored. 

More recent Trek has seemed a bit unsure what to do with the Romulans, probably because the Abrams movies destroyed Romulus via Leonard Nimoy’s voice-over. In Picard, the Romulans salvage a Borg cube, which is really cool but ultimately goes nowhere. In Discovery, the Romulans eventually reintegrate with the Vulcans, creating a merged society. Again, that’s neat, but we don’t see any of it. Maybe we’ll learn more in season five? I can only hope! 

3. The Borg

There is no Star Trek villain more iconic than the Borg. Even non-Trekkies usually recognize the cybernetic look and classic catch phrases like “resistance is futile.” It’s not hard to see why, as the Borg are full to bursting with both novelty and tension. 

On the novelty front, the Borg fill a similar role to later species like 8472 and the 10-C, but without any of that fancy CGI tech. The Borg only have makeup and a plethora of black prosthetics that only look a little like bondage gear. Also tubes. Borg drones are just covered in tubes that could easily snag on something, which is honestly a bit anxiety-inducing whenever they walk close to a wall or piece of furniture. 

Don’t get me wrong, the Borg’s visual effects are a credit to TNG’s costume and makeup department. But since the Borg still have to be humanoid, their main novelty comes from being part of a collective rather than how they look. Star Trek had experimented with joined minds before, most notably with the Binars in early TNG, but nothing on this scale. The Borg’s hive mind makes them completely different than anything our heroes have encountered before.

In the tension department, the Borg are effectively unstoppable when they’re first introduced. Remember a couple of articles ago, when I said the Gorn don’t work as an enemy that can’t be reasoned with? The Borg do. They aren’t interested in traditional conquest or subjugation; they only want to consume. First, they literally scoop cities out of the ground. Later, they transition to assimilating their enemies into the collective. Both are terrifying. 

Against this onslaught, Starfleet is nearly helpless. The Borg send only one ship, but that’s more than enough to blow through the biggest armada we’ve ever seen assembled onscreen. Only some desperately clever thinking from Data allows the Federation to survive, leaving the possibility that the Borg might send two ships next time. As a side bonus, the Borg are flexible as a real-life parallel. They can represent a soulless mega corporation that turns its workers into drones or a communist dystopia that turns its workers into drones. Whatever floats your boat!

All this raises a question: If the Borg are so great, why are they only at #3 on the list? Because everything I’ve told you only covers the Borg’s first few appearances in TNG. After that, the Borg suffer from continuously diminishing returns, as you can only defeat the undefeatable bad guy so many times before it gets boring.

By the end of TNG, the Borg are largely gone as a threat. There’s even dialogue hinting that the collective has been destroyed by the power of freedom.* Voyager reversed course on that, making the Borg into big bads once again. They do okay in this role, but never recapture their old glory. And because of the movie First Contact, the Borg aren’t really a collective anymore, but rather a techno-dictatorship under the Borg Queen. Still scary, but not the unstoppable juggernaut they once were.  

2. Cardassians

When first introduced in TNG, the Cardassians do not have a lot going for them. They come across like wannabe Romulans, trying the same sneaky mind games but without the firepower to back it up. Not only do they lack cloaking devices, but also their warships can be destroyed by a single Starfleet torpedo. When a Cardassian ship attacks with all weapons blazing, Picard and Riker exchange exasperated looks before easily disabling it. 

Fortunately, DS9 sees the Cardassians grow from those humble origins into something great. The flimsiness of their ships is quietly forgotten, and Cardassians are blessed with a plethora of political and espionage skills to make up for any deficiencies in military power. This is exemplified by the Obsidian Order, the main Cardassian spy agency that’s always thinking five or six steps ahead in any confrontation with our heroes. 

During this time, the Cardassians are also developed as a people. Much of this has to do with the recently ended occupation of Bajor, where Star Trek performs the careful balancing act of exploring the motivation behind terrible crimes without minimizing or excusing said crimes. We also see that many Cardassians chafe under the authoritarian rule of a surveillance state, slowly building a resistance against their expansionist government. 

This is already more development than most Star Trek aliens get, but we’re not done yet. Eventually, the Cardassians succeed in bringing down their authoritarian regime, just in time to get invaded by the Klingons. This makes the Federation and Cardassians into uneasy allies, allowing for even more political intrigue. 

DS9’s later seasons see the Cardassians ally with the Dominion before finally switching back to Team Good just in time for the finale. These plotlines show us the full gambit of politics and motivations, from the initial reactionaries who want Cardassia to be an imperial power again to the reformers who know that something better must be built. Sometimes, those are the same people who change over time. 

This is what makes the Cardassians truly top-notch villains: their complexity and depth. Super spy shenanigans are fun, but you won’t find a better-explored alien species in all of Star Trek. By the time of DS9’s finale, we have a precise knowledge of exactly what makes the Cardassians tick. If not for their poor introduction, these guys would definitely be the top pick. Fortunately, poor introductions aren’t a problem for our final contestant… 

1. The Dominion

To this date, Star Trek has only had one series-level villain, and it’s the rightfully feared Dominion. They start subtle, with inconsistent reports of a great Gamma Quadrant power from various aliens that our heroes meet near the wormhole. For nearly a season, that’s all the Dominion are, giving the viewers plenty of time to worry about this mysterious threat. 

When the Dominion do appear in person, it’s clear that their ships are very powerful,* but they don’t invade right away. Instead, they destabilize the Alpha Quadrant through a combination of espionage and diplomacy. They provoke Romulus and Cardassia into launching a doomed preemptive strike that leaves both powers weakened and then manipulate the Klingons into invading Cardassia before it can recover. They convince the Romulans to sign a non-aggression pact and nearly send the Federation spiraling into civil war via a Starfleet coup that our heroes only just manage to prevent. 

This is all before the Dominion is officially at war with anyone. Once the war starts, the Dominion kicks ass and takes names with just the relatively small expeditionary force they first send through the wormhole. Sisko and company manage to keep the wormhole closed after that, but there’s always the threat that even more Dominion forces could come pouring through. 

I could go on, but you get the idea: the Dominion are an existential threat to the Federation, and, unlike with the Borg, there’s no clever science solution that will stop them. The only option is to outfight them, a war that takes more than two seasons to resolve. 

Beyond threat level, the Dominion also gets some top quality development of their motives, history, and internal politics. Originally, the DS9 writers had planned for the Dominion to be a multi-species empire, as a dark mirror to the Federation. That never quite materialized, but we still get three very cool species: Jem’Hadar, Vorta, and Changelings. 

The Jem’Hadar and Vorta were both created by the Changelings, the former as soldiers, the latter as administrators. While we don’t spend as much time with them as we do with the Klingons or Cardassians, we do see some of the complications that come from creating entire species of servants. Sometimes Vorta cloning goes wrong, and instead of a loyal minion, it produces someone with a conscience! The Jem’Hadar can usually be counted on as fanatical soldiers, but some of them see through their programing and realize there’s more to life than being cannon fodder. 

Of course, the Changelings get the lion’s share of development. As beings who can shift form at will, they have the delightfully ironic motivation of wanting to make the galaxy a more ordered place, with none of these chaotic ideas like freedom and determination. Of course, their wars create a lot of chaos, as you can expect conquerors to be at least a little hypocritical. Their shapeshifting powers are also the main reason why the Dominion is so accomplished at intrigue, as they can easily infiltrate any enemy they wish. Or they can just let the fear of infiltration destroy their enemies from within. 

As villains, the Dominion’s main weakness is… nothing. At least, nothing significant that I can think of. They really are superb bad guys from start to finish. And as a cherry on top, they aren’t overused afterward. Once Starfleet defeats them, that’s it, no reason to keep dragging them out for another round like the poor Borg. Sometimes it’s best for everyone if you just let defeated villains retire.

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To keep the length of this series under control, I had to cut out a bunch of aliens who only appear in one or two episodes,* but it still took quite a while to get here. I suppose that’s what happens when I decide to take on a franchise with as much content as Star Trek. While the show’s reputation for one-dimensional villains with rubber foreheads has some merit, Trek is also home to some of the best enemy aliens that scifi has to offer.