The Star Trek universe is vast and features a plethora of memorable alien species that have become an integral part of the franchise. While more established species like the Vulcans or Klingons have made frequent appearances over the decades, others merely appeared once.
Whether they were elusive species that didn’t want to be found, or combative aliens that actively fought the Federation, or just plain cheesy, many aliens have failed to reappear. However, with such an expansive world, even the most obscure alien species has a chance to make a surprise comeback sooner or later.
Flying Parasites
While most of the aliens that the Federation encounters are humanoid in nature, occasionally a more animalistic creature crosses their path. In The Original Series episode “Operation–Annihilate!” the Enterprise crew was attacked by the sinister flying aliens and nearly succumbed to their destructive will.
Despite their cheesy appearance, the flying parasites posed a serious threat to those that were infected by them. Working together as a hive mind, the parasites use their victims as a vessel to accomplish their goals. Unfortunately, the parasite creatures of Deneva haven’t made an onscreen reappearance in the series, though they did appear on several scientific charts on Deep Space Nine.
Kradin
One lesson to be learned from Star Trek is that looks can be deceiving and to never judge someone based on appearance. The Kradin were an alien species encountered by the crew of Voyager when they dealt with the Vori in the episode “Nemesis” .
With a sinister appearance featuring a gaping mouth with big fangs, the Kradin strike a harrowing figure. Despite being described as brutish by their enemy the Vori, the Voyager crew soon learns that they are in fact very helpful. Because the Voyager crew was encountering many species on the other side of the galaxy in the Delta Quadrant, it is unlikely that the Kradin will return soon.
Antedians
Though The Next Generation would also produce many classic episodes, there were a fair number of cheesy moments in the earlier seasons. The Antedian’s lone appearance came in the episode “Manhunt” in which a pair of Antedian diplomats appear on the ship in route to a conference to attain admission into the United Federation of Planets.
With long slender bodies and fishlike heads, the Antedians resembled many of the cheesy aliens of 1950s sci-fi movies. Though they turned out to be up to no good in their sole appearance, their look was a difficult hurdle for many viewers to get over. With an updated appearance, perhaps the Antedians can return to the Star Trek universe some time in the future.
Angosians
While many of the alien races from the franchise are vastly different from humans in appearance, some are utterly indistinguishable. The Angosians were a humanoid race that the Enterprise crew encountered in The Next Generation episode “The Hunted.”
A peace loving race, the Angosians use science to genetically modify their soldiers to be more suited for combat. Unfortunately, they consequences of their genetic tampering leads to many of the soldiers acting out in negative ways. Seen as a mirror of real life and the mistreatment of soldiers after wars are over, the Angosians served their purpose in the one episode they appeared in.
Deltans
Star Trek The Motion Picture attempted to inject many new positive ideas into the Star Trek universe, including several new alien races. The Deltans looked very much like humans except they all sported entirely hairless heads.
What sets the Deltans apart from other races is their uncontrollable sexual attractiveness which must be inhibited with technology. Though an interesting concept, the premise of the Deltans was a strange addition to the Star Trek canon and they didn’t become a popular part of the Star Trek lore.
Armus
Though Star Trek is a show about science fiction and discovery, there have also been a fair number of scary moments in the franchise’s history. Armus was one of the most unique creations of The Next Generation and was a non-humanoid lifeform that was the living embodiment of a planet’s negative emotions.
Appearing only in “Skin of Evil”, Armus proved to be a deadly foe for the Enterprise crew on Vagra II when they encountered him. While not a traditional alien race, Armus is most certainly a living organism of some sort, even if his origins appear somewhat supernatural. Considering the havoc he wreaked in his sole appearance, he would make a terrifying foe to bring back for future encounters.
Cheron
In many ways, the tales of the The Original Series were allegorical and were meant to teach the viewer a lesson about real life. The Cheron were encountered in the episode “Let That Be Your Last Battlefield” in which the Enterprise gets caught up in a political dispute between different factions of the race.
With a half black, half white complexion, the Cheron’s conflict was based exclusively upon racial divisions regarding the way their faces were colored. For the mid 1960s, the Cheron were an important instrument to teach the audience about racism and just how ridiculous such divisions are. However, in modern context, the Cheron are a less useful storytelling tool and could be seen as problematic.
The Swarm
Star Trek Voyager‘s premise of Delta Quadrant adventure gave the writers a chance to dream up a host of new and unusual alien species. The Swarm proved to be a difficult foe to overcome in their sole appearance in the episode “The Swarm”.
Behaving like an insect swarm, the ships of the species attack in packs and their sole purpose is to protect their territory. What made The Swarm particularly interesting was that they were isolationist and mysterious. The lack of information about them kept viewers interested to know more but they wouldn’t return after their first appearance.
Horta
Star Trek showed frequently that alien species could come in all shapes, sizes, and forms. The Horta were one of the most unique looking aliens in Star Trek history and proved to be as curious as they are terrifying when the Enterprise crew encountered them in “Devil in the Dark”.
While many of The Original Series‘ aliens were cheesy by today’s standard, the Horta, with its rocklike texture and volcanic properties, overcame the cheesiness. Despite budgetary limitations, the episode does a good job of hiding the Horta and keeping their appearances scant for better effect. Though they are seen more as pests, the Horta are no doubt a sentient species that could make a return.
Tamarians
Appearing in one of the greatest episodes of The Next Generation, The Children of Tama made the most with their only appearance. “Darmok” saw Captain Picard stranded on a strange planet with an unknown alien that he couldn’t communicate with.
Tamarians are a visually interesting species, with one of the better makeups of the series, but it is their culture that makes them fascinating. In lieu of a traditional language of direct speech, the Tamarians speak in allegorical phrases, referencing historical events symbolically to get their meaning across. Though a memorable species with a fascinating language, there would be very little point in a return for the Tamarians.
