Star Trek Guide

Star Trek: 10 Alien Species Explained

With the recent launch of Star Trek: Picard, there has never been a better time to brush up on one’s knowledge of the alien species inhabiting the franchise’s diverse and colorful universe. Since the original series, learning the intricacies, curiosities, and nuances of strange alien cultures has been one of the pervading joys of Star Trek fandom.

The idea of a future where humans are successfully navigating such vast societal and physiological differences is hopeful and inspiring, core to Gene Rodenberry’s vision of a better and more moral human race. This list examines ten species that the Federation encountered across series.


Changelings are amorphous beings, able to shapeshift into any corporal form due to a quantum and cellular structure described in Deep Space Nine as a ‘morphogenic matrix’. They do not require food to live and seem to have an indefinite lifespan. Core to their culture is the ability to join together when in liquid form, something referred to as the ‘great link’. This collective existence is considered superior to that of the individual.

In Deep Space Nine, Head of Security Odo is a changeling who has separated from his species, and who has a somewhat fractured sense of identity as a result. Having been raised by Bajorans, he chooses to maintain a human-like appearance in order to better assimilate with his peers but also has personality traits typical of his race, such as a tendency towards order and discipline.


The El-Aurian are a near-extinct species who are physically identical to humans, but who are capable of a lifespan spanning several centuries. They were known as a wise and enigmatic race of listeners and explorers, and visited earth long before humans were aware of alien civilizations or had warp capabilities. The El-Aurian homeworld was decimated by the Borg, who killed the people in their millions and left just a few survivors scattered throughout the universe.

One of these is Guinan, the bartender at Ten Foward in The Next Generation. Guinan was played by Whoopi Goldberg, who publicly accepted an invitation from Patrick Stewart to join the cast of Picard, so we should be seeing more of this race shortly.


With blue skin, white hair and dexterous head antennae, Andorians are native to Andoria, an icy moon in a system neighboring planet Vulcan’s. Despite making their first appearance in the original series, they are somewhat underused in the Star Trek universe, featuring most prominently in the short-lived Star Trek: Enterprise, which establishes them as founding members of the United Federation of Planets. Prior to this, the Andorians had limited contact with other races and a history of conflict with the Vulcans.

Although they possessed an initial mistrust of humans, who they pejoratively refer to as ‘pink skins’, in Star Trek: Enterprise, Captain Archer is able to form a friendship with Andorian starship Captain Thy'lek Shran, foreshadowing the future alliance between the species.


The Sheliak are another non-humanoid race who debut in Star Trek: The Next Generation. They are bizarre-looking, consisting of a black, nebulous shape with metallic-like scales and no obvious face. They are hostile towards humans, with a dislike of human languages, in particular, deeming them basic and irrational.

Since the Sheliak despises ambiguity within communication, the Federation was able to avoid conflict with them by agreeing on a highly specific and complex treaty, though they do have a brief disagreement with the Enterprise in Next Gen.


According to Star Trek lore, Fleetwood Mac co-founder Mick Fleetwood was so desperate to appear in the series that he agreed to cameo in The Next Generation as an Antedian, a never-seen-before species that resemble a kind of fish/human hybrid. 

They are bipedal, with blue skin, various fish-like facial protrusions, and large side-facing eyes. Despite being capable of spaceflight, they can only physically endure it by entering a comatose state, and must replenish themselves after long journeys by eating large amounts of their preferred food - fish. They are also highly susceptible to telepathy, which is why Betazoid Deanna Troi is able to quickly expose two Antedians aboard the Enterprise - Mick Fleetwood and his companion - as secret assassins.


Like a lot of alien races in Star Trek, the J’Naii are only physically distinguishable from humans by a series of facial ridges, in addition to a distinct lack of eyebrows and uniformly brunette hair. Culturally, they are very different, however, as they are a species that completely reject the notion of gender.

They were introduced in The Next Generation in honor of Gene Rodenberry’s desire to address LGBT issues, and depict a human race who've come to accept all minority groups. In 'The Outcast', Riker becomes romantically involved with a J'Naii who is increasingly ostracized for identifying with the female gender. This episode must be one of the earliest pop-culture explorations of an issue that has recently taken center stage.


The Anear are a small race of people descended from Andorians and native to the 'Northern Wastes' of icy planet Andora, a region with sub-zero temperatures uninhabitable to most biological life.

They have much paler skin than Andorians and milky-white eyes, owed to them being completely blind, and are so reclusive that they were once considered a myth on Andora. Thus far, they have only been depicted in Star Trek: Enterprise.


Nausicaan's are a large and imposing race with great physical strength and a reputation for space-piracy. They look a little like the 'Kradin', an alien that appeared in Voyager and was criticized as being too similar to that of the Predator franchise. They have sharp teeth or tusks at either side of their mouth and a number of facial ridges.

Their most famous appearance is in The Next Generation, when a group of Nausicaan pirates get into an altercation with a young Picard over a game of 'dom-jot'. A fight ensues and Picard is stabbed through the heart with a Nausiacaan sword, leading to him requiring an artificial heart - something that proves important to the plot of Next Gen season six.


When a group of Changelings founded 'The Dominion', an interstellar state committed to imposing totalitarian control all of the known universe, they required footsoldiers - administrators, scientists, and field commanders - to carry out their will. So they used genetic engineering to create the Vorta, taking a small, ape-like species and transforming them into humanoids with elongated ears, superior hearing and violet eyes. If killed, a Vorta is replaced with an identical clone who retains their memories.

This artificial creation process seems to have left the Vorta with a limited appreciation for human pursuits like pleasure, aesthetics, and culture. Nevertheless, they are an intelligent race, whose commitment to their creators is absolute.


Gomtuu is introduced in a Next Gen episode based on Sci-Fi novel Tin Woodman, about a sentient spacecraft. It is a millennia-old intelligent life form who may be the last of its mysterious race, with a warp drive, transporter capabilities, artificial gravity and other features of a traditional starship. However, Gomtuu is also a living, feeling creature with immense telepathic abilities, existing symbiotically with its crew.

After Gomtuu's crew are killed in an accident, the creature aimlessly drifts through space, eventually deciding to end its lonely existence via suicide, in an explosion wrought by a star going supernova. Its story is among the most tragic of any alien race depicted across series.