The budgets on the original three seasons of Star Trek were miniscule, which meant that the depiction of alien races tended to favour humanoid species that could be created with minimal make-up and effects – pointy ears, daft headgear and colourful spandex were usually the order of the day. Nevertheless, two of these alien races evolved into some of the richest and most developed in all science fiction – the logical Vulcans and warlike Klingons, both hugely popular with fans. Here are 10 of our other original series favourites:


Andorians: Blue-skinned, white-haired humanoids with a pair of antennae (of obscure purpose) on the tops of their heads. One of the founding races of the Federation, they turn up in Season Two’s Journey to Babel (along with Spock’s mum and dad) but didn’t really come into their own until the ill-fated Enterprise series revived them in 2001.

Denevan neural parasite: Looking like flying pancakes with an attitude problem these highly unpleasant life forms did for most of the colonists on Deneva, including Captain Kirk’s brother Sam in Operation Annihilate. They turned out to be something like oversized brain cells that got together to form a collective intelligence and were fortunately vulnerable to ultraviolet radiation.

Gorn: Yes, it’s a guy in a rubber lizard suit wearing a sort of mini-dress and probably didin’t look all that scary even in 1967. Nevertheless, there’s just something about the lumbering, hissing Gorn that’s hard to resist, and his one-to-one face-off with Kirk at Vazquez Rocks in Arena is a great Trek episode.

Horta: While it looks like a huge ambulatory pizza and has an unpleasant habit of killing miners, the Horta turns out to be a highly intelligent creature that’s simply protecting its young. It would have been great to see one of the youngsters signing up for Starfleet and joining the bridge crew.

M-113 creature: The Man Trap, the first episode of TOS ever screened, introduced the sort of horrible-looking alien monster that didn’t actually ever show up very often on the show again. The ‘Salt Vampire’ had suction-cup fingers and a mouth like a lamprey, as well as the ability to appear as an alluring female (like McCoy’s old girlfriend Nancy Crater) in order to lure its unsuspecting prey to their deaths. This being Star Trek, though, the poor old M-113 creature is a tragic figure, last survivor of an intelligent (if hideous-looking) race.

Mugato: A sort of big, white-furred gorilla-thing with a spike on its head, poisonous fangs and evil-looking claws. It lives on the planet Neural, where Kirk has a nasty brush with one that nearly results in his death in ‘Nam allegory A Private Little War. The Mugato was designed and played by Janos Prohaska, the same long-suffering make-up artist who had crawled around under the Horta costume.

Romulans: Close relatives of the Vulcans who remained unseen even after a war with the Federation, they turn out to be a martial but essentially honourable race after the Enterprise’s first encounter with them in Season One’s brilliant Balance of Terror. Mark Lenard – who went on to play Spock’s father Sarek – makes his Trek debut in this episode as Kirk’s opposite number in a tense battle that owes more to submarine war movies than space opera; his admission that in another situation he and Kirk could have been friends is a classic, and moving, bit of anti-war Trek.

Talosians: Captain Pike’s captors in Star Trek pilot The Cage and Season One’s The Menagerie, parts 1 and 2, these eerily asexual aliens came from a long tradition of extraterrestrials boasting outsized crania. At school in early 1970s they were fondly known as the Bumheads.

Tellarites: Pig-faced, argumentative aliens first glimpsed in Season Two’s Journey to Babel, in which the Enterprise ferries an ill-assorted bunch of alien diplomats to a vital conference.

Tholians: Perhaps the strangest and most mysterious of the original series’ alien races, the Tholians were a territorially aggressive non-humanoid species of vaguely crystalline form (if memory serves, Enterprise later revealed them to be six-legged and sort of insectoid too). They whizzed around in funny little ships capable of weaving an ‘energy web’ around the Enterprise; weird and very cool.