There exists a variety of extraterrestrial life in the fictional universe of Star Trek. Much of this life is humanoid, although there are exceptions.
The best-known Vulcan is Spock (played by Leonard Nimoy), the son of Vulcan ambassador Sarek and human mother Amanda. He is the first officer on the U.S.S. Enterprise under Captain Kirk, and later becomes an ambassador like his father. Being part human, Spock struggles with keeping his emotions suppressed.
Vulcans were the first aliens to make contact with humans (this event was depicted in the movie Star Trek: First Contact), and most human-manned starships include one or more Vulcans in the crew. They appear in all Star Trek series. Vulcans live a long time compared to humans, and have the ability to "mind meld", or temporarily join minds with another being. Their greeting "live long and prosper", along with their manner of holding their hand up in greeting with the second and third fingers together and fourth and fifth fingers together forming a "V" shape has entered popular culture. The salute was created by Leonard Nimoy (a neo-orthodox Jew) and is a single handed copy of the two handed gesture used when reciting the Aaronic blessing in Numbers 6:22-27 . The gesture is intended to signify the Hebrew letter shin, the first letter in "Shekhina" or the presence of God. The verbal greeting "live long and prosper" is taken from the same passage.
Klingons are a war-like race from the planet Kronos. In the original series Klingons were often enemies of the Federation. In Star Trek VI: The Undiscovered Country, the Klingons and the Federation begin peace talks.
The best-known Klingon is Worf, the security officer on the U.S.S. Enterprise-D of Star Trek: The Next Generation. He also makes appearances in Deep Space Nine.
Romulans are a secretive race from the planet Romulus. Before the events of the original series, humans and Romulans fought in a destructive war, after which a neutral zone was established between their areas of space.
In the original series Romulans were frequently in battles with the U.S.S. Enterprise. In the original series, it was revealed that they were distantly related to the Vulcans (most notably indicated by Romulans having pointed ears like Vulcans). In Star Trek: Nemesis, the Romulans finally decide to negotiate a truce with the Federation. However, in Star Trek (2009), it is revealed that some years after the events of Nemesis, a nearby star becomes a supernova, and destroys Romulus.
The Ferengi are an impish race of sexist people primarily concerned with making a profit. Being businessmen is virtually a religion to them. Their Rules of Acquisition is a list of 285 rules ranging from Once you have their money, you never give it back (No. 1) to No good deed ever goes unpunished (No. 285) and include War is good for business and Peace is good for business (Nos. 34 and 35).
The Ferengi first appeared in Star Trek: The Next Generation and the best known is Quark, a resident of Deep Space Nine. They have also appeared in Voyager and Enterprise.
An alien race physically characterized by gray skin with black hair and ridges down their neck and shoulders and a spoon-shaped structure on their foreheads. A very militaristic race. Their legal system mimics that of Communist China where the accused is assumed guilty and the trial serves to show the defendants' guilt rather than giving them a chance to defend against the charges. This is used (as on Earth today in China) to reinforce the supremacy of the state. Cardassian crime novels are found boring by most Earth standards since everyone did it, the mystery is to figure how everyone is guilty. In this vein, Cardassians would prefer Agatha Christie novels such as Ten Little Indians or Murder on the Orient Express, since nobody in these novels was actually innocent, rather everyone was either complicit or actively guilty.
- Cardassians had their own secret police called the Obsidian Order which were used to intimidate the citizens of Cardassia into obedience and to harass, abuse and arrest any individual thought guilty (usually innocent) of criticizing the state or its policies.
- The Cardassians conquered and enslaved many worlds, most prominently Bajor. They built the Federation space station Deep Space Nine (which the Cardassians called Terak Nor) as a slave labor facility where Bajoran slaves processed or for Cardassian use.
A humanoid race physically characterized by small ridges on their noses. Male Bajorans usually have their hair slicked back. During pregnancy, Bajoran women suffer from uncontrollable bouts of sneezing rather than morning sickness. Bajoran women gestate for five months, as opposed to the nine months of human women, due to high vascularization between the fetus and the mother. During childbirth they must be extremely relaxed, and they feel little or no pain during the process.
Bajorans are a very religious race (one of the few in Star Trek). Centering around the Orbs—objects of an alien origin believed to have been sent by the Prophets They believe the wormhole situated near their planet of Bajor is the home of their Gods whom they refer as the Prophets and that Captain Benjamin Sisko is their Emissary. Their religion, centering around the Orbs—objects of an alien origin believed to have been sent by the Prophets ( called The Way of the Prophets) is organized much like the Catholic church with a female leader called the Kai (similar to the Pope) at the head of their church who has a great deal of influence over the Bajoran Provisional Government but no real power, as well as Vedeks (Cardinal or Bishop, often male), Mylar (priest or minister), and Prylar (Monk). There is also a Vedek Assembly (Like the College of Cardinals).
They were once enslaved by the Cardassians and forced into labor camps like Terak Nor (now Deep Space Nine) to process ore for Cardassian use. Many of them revolted and formed a revolutionary group to fight Cardassian oppression much like the French resistance during WWII, many of whom remain actively hostile to Cardassia.
Some well known Bajorans are Colonel Kyra Nerys, Ensign Ro Laren, Li Nalas, Tora Ziyal (half Cardassian), Kai Opaka Sulan and Kai Winn Adami.
A race of shape shifters located in a region of space known as the Gamma Quadrant. The Founders genetically engineered most of the sapient races in the Gamma Quadrant, and are worshiped by many as gods. The Federation first venturing into the Gamma Quadrant through a wormhole started a war, with the Federation and most inhabitants of the Alpha Quadrant on one side, while the Founders and their creations were on the other.
The most well known of this species Deep Space Nine's chief of security Odo.
The Borg are not actually a separate race, but a "collective" of beings forcibly "assimilated" from other races and turned into drones with cybernetic implants.
Their first appearance was in the season two episode of Star Trek: The Next Generation, "Q-Who?" in which the entity known as Q sends the Enterprise-D into the path of a Borg cube. In the two-parter "The Best of Both Worlds," the Borg enter Federation space, intending to go to Earth to assimilate the planet. This two-parter introduces the concept of assimilation with it happening to Captain Picard. He becomes designated Locutus of Borg, and acts as an ambassador of sorts. The crew of the Enterprise-D eventually restores Picard, although the effects of the episode resonate throughout the mythos of the franchise (most notably in the Star Trek: Deep Space Nine pilot episode "Emissary", in which Commander Jake Sisko, one of the main DS9 characters, lost his wife Jennifer during the Battle of Wolf 359, in which the Borg cube from "The Best of Both Worlds", under the direction of Picard as Locutus, single-handedly all but annihilated a Starfleet armada sent to destroy the cube, an incident for which Sisko had since held Picard responsible, even though Picard was being controlled at that point by the Borg collective).
In Star Trek: First Contact, the Borg Queen is revealed as the leader of the Borg. This makes the Borg comparable to an insect colony.
They were introduced in Star Trek: The Next Generation and were also prominent in Voyager, where one rescued drone, Seven of Nine (born as Annika Hansen), becomes a member of the ship's crew following the departure of previous crew member Kes.
The main Borg type of ship is a massive cube from which they attack other ships and take the crew captive, forcibly turning them into Borg drones.
They announce themselves with the phrase "resistance is futile", which has entered popular culture.