What Were Star Trek's Creepiest Creatures?

In honor of Halloween, let’s ignite a little debate.

What were Star Trek’s freakiest/scariest creatures or characters? We’re talking about everyone and everything across the entire franchise, from The Original Series to the present.

Below are several of our favorites, in no particular order whatsoever. We’re just trying to get the party started.

The M-113 Creature aka The Salt Vampire

Oh man, the old-timers out there can’t forget this one. And how could they? The salt-craving entity from “” — the very first Star Trek episode that aired on NBC — stands the test of time.

It’s creepy and horrific and effective all these years later. The last of a vaguely humanoid species was willing to kill to satiate its own hunger.

Zombie Vulcans

We can all debate the merits of the episode “” and whether or not the zombie Vulcans were thoroughly scary or completely laughable, but come on, folks, you’ve got to appreciate the fact that the writers and producers went there.

However, for the crew of the Seleya, the Trellium-D that they were exposed to in an asteroid field started to poisoning their Vulcan nervous system. Our level-headed, unemotional Vulcans have been reduced to a homocidal, zombie-like shell of what they used to be. "Impulse" takes us on a journey as we witness T'Pol slow descent into emotional paranoia as her condition deteriorates.

The Doctor

Everyone’s favorite EMH was usually cranky and impatient and pretty much forever holier-than-thou. But in the “” episode of , Robert Picardo took his always-superb performance as The Doctor to a whole new level, adding a layer of genuine menace once he fiddles with his program and ends up becoming far more Mr. Hyde than Dr. Jekyll.

Bonus points for UPN’s teaser trailer, which promises “Diagnosis: Terror.”

Redjac aka Jack the Ripper

episode “” remains one of the show’s finest hours, at once compelling and scary as hell. Of course, it helped to have a Robert Bloch teleplay, Joseph Pevney directing, James Doohan delivering one of his best-ever performances as Scotty, and a thoroughly engrossing guest-star turn from the late John Fiedler as Hengist/Redjac/Jack the Ripper.

The non-corporeal lifeform survived for centuries by journeying from planet to planet and feeding off fear he created during his murdering sprees. Among the murderous identities Redjac has held are Jack the Ripper on Earth, Kesla on Deben II, and Beratis on Rigel IV.

Bonus scariest fact of all — Fielder was probably best known as the voice of… the adorable Piglet in many of Walt Disney’s Winnie the Pooh film and TV productions.

The Borg Queen

Though the Borg were eventually humanized, so to speak, by the end of and certainly on Voyager, for a long time they served as TNG’s most fearsome enemy. Fans argue non-stop about which Borg induced the most goosebumps, and a case can definitely be made for the ones in “,” but we’ll go with the Borg Queen as portrayed by Alice Krige in . The actress made the character simultaneously creepy, sensual, repulsive, and magnetic, and there was just no taking your eyes off her any time she was on-screen.

The enigmatic Borg Queen is the central locus of the Borg Collective. She brings order to the legions of voices within the Hive mind and provides a common direction. The Queen spends much of her time in her "lair" with her head and spinal column residing in a special alcove. When she emerges, she will "re-assemble" herself into a predominantly artificial body — the arms, legs and torso appearing to be entirely synthetic, while the head and shoulders seeming to be organic, but with substantial cybernetic implants.

The Ceti Eel

OK, we know that there are lots of other Star Trek aliens and creatures that gave us the heebie-jeebies, from Garak to the Devidian and from The Clown to Balok. And we know there are lots of other frightening Star Trek adventures, ranging from episodes like “The Lights of Zetar,” “Catspaw” and “Frame of Mind” to “Sub Rosa,” “Night Terrors” and “Schisms.”

But, honestly, nothing can top the squirm-inducing, scream-worthy Ceti Eel as seen in . It’s disturbing to watch them enter the ears of Chekov and Terrell, terrifying to hear Chekov's scream, and then, later, just plain gross to look on as one, covered in blood, plops out of Chekov’s ear. That's because it wraps itself around their cerebral cortex. Oh, and for the record, the similar creature that Nero trotted out in Star Trek (2009) was a Centaurian slug, not a Ceti eel.

The Vidiians

Nothing is more terrifying than wearing the flesh of another.

The Vidiians are grotesque as they are depraved. First introduced in "," the once space-faring species known as educators, explorers, and artists became afflicted with a disease that killed thousands each day. The only way to stave off the phage that eats away at their tissue and organs is to harvest organs. In dire circumstances, they've shown the lack of conscience, as they've become cold and unrelenting after suffering from nearly two millennia, shunning the arts in pursuit of fighting the virus.

In one vile act, a Vidiian surgeon splits B'Elanna Torres, in "," into two — her Klingon form and her human one. After that violation, the surgeon kills off one of B'Elanna's crewmate and wears the skin of his face in an effort to seduce the Klingon B'Elanna.

The Gorn

The antagonistic Gorn are more than just fierce combatants. As seen in , we soon discover the formidable species views any sentient being that isn't Gorn as a potential food source or host, with the Gorn luring and trapping other species on their breeding planets.

From birth, they are vicious as they are violent, with hatchlings bursting out of their hosts' bodies before fighting among each other for dominance, to ensure only the strongest of their kind survives. As they grow, they soon develop venom ducts that allow them to blind and infect future hosts with parasitic eggs, perpetuating the cycle.

Mother Parasite

As seen in The Next Generation's "," Captain Picard and the Enterprise-D learn something is rattling the highest levels of Starfleet. At a nauseating dinner, Picard learns Starfleet Command has been infiltrated and controlled by parasites. Unfortunately for the Starfleet victims, the parasites wrap itself around their host's brainstem, whereupon removal would instantly kill the host.

With the dinner ruse interrupted, Picard and Riker chase down a parasite and find it entering inside another officer. As they set their phasers to kill, the beam begins to dissolve the officer's chest cavity, exposing the large, aggravated Mother parasite which was living inside the officer along with a number of its offspring.

We'll never know how deep the invasion ran as the Mother parasite was able to send a homing beacon to an unexplored region of our galaxy before being destroyed.

OK, so what are YOUR favorite scary Star Trek creatures or characters?