JOTOKI

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Jotoki are non-humanoid sentient communal organisms that developed a space faring civilisation.
The Jotoki resemble large, spindly starfish. They are born as small aquatic swimmers, most of which are eaten by predators; in time, survivors will merge in groups of five to form one collective organism, which grows into an arboreal creature; its tails become arms, and its fins differentiate into fingers. When it grows large enough, the Jotok imprints itself on an adult and enters a stage of rapid learning and brain growth. A Jotok who desires a family can simply go into the wilderness and "harvest" an adolescent. Unimprinted adult Jotoki are considered feral, and regarded as little more than animals. Since the five subunits that make up one Jotok individual are not necessarily genetically related, reproduction does not require sex; a Jotok can simply find a pond and deposit its offspring to begin the cycle again.
The Jotoki were experts at trade. Their interstellar trade empire was quite developed for its time, but when the Jotoki attempted to use the Kzin as mercenaries, the Kzin revolted and conquered the Jotoki. Before their enslavement, Jotoki operated in groups called "clanpods", as part of their former planet-wide tradeweb. Details of this arrangement are not known. Jotok technological specialties included gravity polarizers, linguistics and biotechnology. They had the ability to force-grow clones to adulthood. The Kzinti believe that there is a free Jotoki fleet wandering amongst the stars, which would have provided their most strenuous opposition.
After the Man-Kzin Wars, humans recovered some Jotoki swimmers in an attempt to breed a free Jotok species.
Source: Larry Niven, Known Space Universe, (informations adapted from the Wikipedia entry), "The Asteroid Queen", by Jerry Pournelle and S.M. Stirling, "In The Hall of the Mountain King", by Jerry Pournelle and S.M. Stirling, "The Heroic Myth of Lieutenant Nora Argamentine", by Donald Kingsbury

DORCONS

Planet of Origin; Dorca, in another galaxy of the Local Group, the same as Psychon.
The Dorcons are a humanoid species looking much like humand who have developed an expansive advances civilisation. They are conquerors who have built a vast interstellar empire. They have been known to have attacked Psychon in the past and use Psychon brain stem to achieve immortality.
Planet Entra and its lunar penal colony Ellna are probably part of the Dorcon empire.
Source: Space: 1999

ILLUMIDAS / HUMANOIDES

The Illumidas are an aggressively militaristic humanoid species that developed an interstellar civilisation in the 2900ies, at which time they invaded the Earth. They have a large space fleet and move through space planet by planet, seeking to subdue and exploit other worlds. They are green skinned and only males of the species were ever seen.
They were wiped out by the Arcadians after an attempt to misuse the powere those had betwoed on them.
Source: Leiji Matsumoto, Space Pirate Captain Harlock universe in "Arcadia of my Youth" movie and "Endless Road SSX" TV seies.

YOLU

Planet of Origin: Pa'ri

The Yolu are long lived isolationist humanoid species which has developed an highly advanced space faring civilisation some 3000 years ago. Their recorded history goes back 5000 years, and 4000 of those have been of stability. In the twenty-third century, they were members of the League of Non-Aligned Worlds and are later members of the Interstellar Alliance.
They are extremely devoted, yet religiously tolerant.All Yolu religions espouse different viewpoints on the expression and form of the Coo-tah, an energy field, they believe, created by all living things. The Yolu Government, called the Ingyo, is composed of 15 priests and priestesses that have attained a higher understanding of the Coo-tah. They also are famed for the Mutai, a mode of settlement of differences between two factions settled with the loss of one life instead of thousands.
Source: J'Michael Strasczinsky, Babylon 5 universe

BRAKIRI

Planet of Origin: Brakus

Brakiri are a humanoid alien species which has developed interstellar flight technology in 2111 and has expanded into an interstellar civilisation as of the twenty-third century when they were members of the League of Non-Aligned Worlds and later, of the Interstellar Alliance.
Brakiri society is based on trade and economics, their governing body being a consortium of several mega companies but criminal syndicates are power that have very high influence on the Brakiri way of life. They have have a reputation amongst the other races of being pack rats and scavengers
The Brakiri are nocturnal and look remarkably like humans with enlarged foreheads, ridges above their eyes and a hairline positioned in the further back of their scalp. [edit]
During the Shadow War of the twenty-thrid century, they made an alliance with the Shadows, believing it would ensure their safety but the Shadows eventually turned and attacked them, proving the Shadows were on no one's side but their own. The Brakiri then joined the alliance dubbed the Army of Light, contributing much of their remaining resources to its cause.
One of the most notable cultural events in the Brakiri society is the religious celebration called "day of the dead". It happens every 200 years when a comet passes the Brakiri homesystem. Every Brakiri has to be on home soil, either on Brakus, one of the colonies or just a rent area. The Brakiri use this day to interact with dead people, mainly family members or friends but sometimes even enemies.
Brakiri's first contact exprerience was with mankind through Earth's radio waves travelling trhough space at the dawn of the third millenium.
Source: J’Michael Strasczinsky, Babylon 5 universe

SHADOW SERVANTS: DRAKH

The Drakh are stocky sentient reptilian bipeds with an heavy endo and exo-skeletal systems and thick dark grey scaly skin. They may have some kind of group mind as they can communicate with other Drakh over long distances.
The Drakh are dark servants for the race of First Ones known as the Shadows. Much like their masters, they have various agents working for them, and apply technology to mask their appearance. They use the same Phasing Technology as the Shadows to Phase in and out of the physical universe. It remains unknown if they developed a space faring civilisation of their own prior to their afiliation to the Shadows or if they were nurtured by them to their present state.
Speculative litterature postulates that after the Shadow War of the 23rd century and the departure of the Shadows, they'll be trying to take their role as interstellar pupetmasters.
Source: Babylon 5 universe

PIERIN

Planet of Origin: Pierin, in the Reticulus constellation
A bipedal species that developed a small spacefaring civilisation and was enslaved by the Kzin. Pierin are nosy horned avians with wide wings. They speak in raspy screeches and atonal clicks which are difficult to understand for other species.
SOurce: Larry Niven, Known Space universe, The Ringworld Companion (a supplement for the Ringworld Roleplaying Game) pp. 18-9

KDATLYNO

Planet of Origin: Kdat
Kdatlyno are an extraterrestrial species which was conquered by the Zkin before they entered the space age. After their liberation from the Kzin, they established themselves on several worlds. They are a ten feet tall massive and powerful bipeds with muscular build, long arms and flat feets, urved silver-tipped claws at knees and elbows, rough scaly brownish skin, retractile claws on the knuckles of their huge hands. They have no eyes but a goggle-shaped tympanum and constantly emit a supersonic whistle through their large mouth, having evolved echolocation rather than vision.
They are famous for their touch-sculptures Source: Larry Niven, Known Space universe, Grendel (short story), in Neutron Star Picture by Bonnie Dalzell, Copyright © 1975

SILVER GHOSTS

Planet of Origin: In the Milky Way

The silver ghosts consist of a set of symbiotic organisms inside a super-reflective shell that efficiently maintains internal temperature and reflects radiation. The silver ghosts are therefore able to exist in space without additional vehicles. They are known for their pursuit of physics, particularly their experiments regarding changing physical constants in regions of space.
Speculative litterature postulated that at some point in the future, they could eventually be conquered and nearly wiped out by humans, who would adopt their silver skin technology for their own purposes.
Source: Stephen Baxter "Xeelee Sequence"

SQUEEM

Planet of Origin: In the Milky Way
The squeem are space faring group minded aquatic species. They are not especially intelligent or advanced, and resort to stolen technology from the Xeelee, for instance, the hyperdrive.
Speculative litterature postulates that They could be the first extrasolar intelligence contacted by mankind, and by the time of that contact, they would occupy the solar system and enslave the human race.
Source: Stephen Baxter, Xeelee Sequence

QAX

The Qax species is comprised of very few and long lived individuals which developed an advanced spacefaring civilisation.

"Qax biology is based around chemical hyper-cycles embedded in convection cells. A Qax is millions of such cells arranged on the sea surface in a branching pattern covering several miles. Each cell is as wide as a coffee can lid, languidly bubbling like chocolate with nested eddies down to the microscopic level; they're highly organized, living storms." (Taken from Daily Kos. Thanks!)
Being composed of convection cells, a Qax requires complex life support and can be damaged easily - therefore their contact with other species is usually indirect.
The Qax had a longstanding alliance with the sentient Spline ships who carried them around the galaxy.
Hypothetical Litterature postulated that Circa 5000, the Qax would encounter humanity and a brief war would be fought leading to the occupation of Earth and its colonies by the Qax until they were forced to leave dure to their hommweorld's destruction.
Source: Stephen Baxter, Xeelee Sequence
Thanks to Karen Wehrstein for the great Qax picture

PHYLOSIANS

Planet of Origin: Phylos, on the edge of the galaxy
The Phylosians are a sentient species of mobile plants who developed a technologically advanced civilization. They have a naturaly long life span which they extended with their science. While they had not yet ventured much outside their hoemworld, they had developped theoretical knowledge of interstellar travel and had even devised a plan to build a fleet of large military ships to ensure peace in their interstellar neighborhood. Exposure to a staphylococcus strain of bacteria brought by a human explorer stopped their effoert and wiped out most of them in the 22nd century. By cloning himself, the explorer was able to cure the phylosians over the course of the next century.
Source: Star Trek the animated series "The Infinite Vulcan"

EDOSIANS / EDOANS / TRIEXIANS

Planet of Origin: Edos in the Triangulum constellation on the rim of the galaxy.
Edosians are a tripodal species, with three arms, three legs and three fingers on each hand.
The Edosians are a peaceful,long-lived species worshipping many gods who have developed a class-less society in whihc all are considered equals. Edos has never been involved in a war. its technology is as advanced as Earth's. The architectural style of its cities is strictly functional rather than esthetically pleasing.
In the 23rd century, they were allies of the Federation of Planets. Contact was already established with Earth or an affiliated species in the mid-22nd century (as Knowledge of the Edosian suckerfish among Humans would suggest, as mentioned in Star Trek: Enterprise)
Source: Star Trek the Animated series, Lincoln Enterprises Star Trek Catalog Number 5

BUBBLE CREATURES

The bubble creatures are a non-humanoid spacefaring species resembling a gnarled, melting lump of greenish-brown flesh, with several pulsating multi-faceted 'bubbles' of various colors protruding from various spots on their body. They communicate by electric arcing on the surface of their bubbles.
Source: Lost in Space "The Derelict", "Prisonners in space"

SKUXXOIDS

Skuxxoids are an intelligent reptilian species that often sell their services to the highest bidder as mercenaries for credits. They have scaly skin and stand from 4 to 5 meters high. Skuxxoids have been known to be hired by Quintessons ("Five Faces of Darkness, Part 1 & 2) and Cybertornian Dececpticons (Chaos, Starscream's Ghost, Grimlock's New Brain). They tend to use large asteroid ships as their primary mode of transport and it is quite probable that most of their technological advancement came from scavenging or trading their serivice against tehcnological upgrades.
Source: The Transformers animated series

LACTRANS

Planet of Origin: Lactra VII, Milky Way
The Lactrans are a civilization of highly advanced telepathic 30-meter-long slug-like lifeforms.
Source : Star Trek the Animated Series: "The Eye of the Beholder"

SHELIAK

Planet of Origin: A planet in the Shelia / Beta Lyrae star system (ca. 882 lightyears from Earth)
The Sheliak are a reculsive species that developped a space faring society as of the 23rd century. Althought they travel through space and have colonised other planetss, they try to avoid contact with other species whenever possible.
Not much is known about the Sheliak social system but colonists refer to themselves as "the Membership" and have a governing body called "the Corporate".
Unlike most humanoids, the Sheliak prefer to exist in an environment that is the same temperature as their bodies. (TNG: "Starship Mine")
Source: Star Trek The nExt Generation (TNG: "Starship Mine") (TNG: "The Ensigns of Command" for reference to homeworld)
Note: The Thrakallans seen in Babylon 5 also come from the Beta Lyrae system.

MEDUSANS / VISALAYANS

Planet of Origin: Medusa (Visalayan), orbiting the G8 star Xi Hydrae, 129 light years from Earth.
The Medusans are an highly evolved peaceful telepathic non-corporeal species. The visual impression they leave upon those they meet is so utterly hideous that the sight of a Medusan renders most humanoid lifeform mad. Some species are known be able to withstand their sight but only through the use of a specially filtered visor. For these reasons, Medusans usually use an opaque carrier pod when interacting with other species. The Medusans was a member of the Federation of Planetes in the twentietn century and had limited contact with some other species.
. (TOS: "Is There in Truth No Beauty?")
Source: Star Trek TOS: "Is There in Truth No Beauty?"

ABBAI

Planet of Origin: Ssumssha (Abba IV)
The Abbai are a reptilian humanoid species led by a matriarchal regime who have developed a space faring civilisation. In the twentieth century, they became members of the League of Non-Aligned Worlds and then of the Interstellar Alliance.
“The Abbai civilisation is over six thousand Earth Years old and is regarded as a model of tolerance and respect and has eradicated all poverty and inequity on their world. Although the Abbai are ruled by a single gender, this is simply a fact of Abbai biology that the females outnumber males five to one, though the males are in no way considered inferior and are able to participate in all areas of society, with the exception of the government itself. This arrangement seams to work as it has remained stable for over four millennia and most male seam more interested in pursuing artistic, scientific or academic professions over politics. The Abbai are a very technologically adept civilisation and have possessed the capability for interstellar travel for over eight hundred years. They however specialise in agriculture, medicine, communication systems and computer software. Though they are a peaceful race who do not believe in conquest or violent expansion, they are by no means total pacifists and are quite capable of defending themselves. Most of their weapons are designed around non-lethal but formidable reactive force. Their ships and planetary defences are capable of generating massive force shields, capable of withstanding most assaults. They are also proficient and electronic warfare, intercepting and jamming enemy communications. The bulk of the Abbai Matriarchate's defence strategy however lies in their good relations with other worlds and their numerous interplanetary alliances from which they can muster a defender in case of attack or if necessary hire other races as mercenaries… Religion is highly prized among the Abbai, as is tolerance and mutual respect. As such their sixteen distinct religious hold no rivalry towards one another. The most dominant belief system on Abba IV is Oulai, the worship of wind and water. Unlike most other races the Abbai to not worship divine being(s) but instead revere the natural elements (stone, sand, plants, mountains etc.) with the exception of Kolai; the worship of logic and knowledge.” (from the Babylon 5 Wikia)
Source: Babylon 5 universe, Babylon 5 Wikia

STREIB

The Streib is a secretive humanoid species which developped a space faring civilisaton. They are distant relatives of the Vree but it remains unknown when or how both civilisations came to evolve on different worlds. The most obvious difference between the two races is the configuration of the eyes. The Vree's eyes are pure black, whereas the Streib's eyes have a red slit down the center. Both culture share the trait of kidnapping other species and examining them onboard their ships. Streib alos share a lot of physical resemblance with Zeners and other Shadow servants.
Source: Babylon 5 universe