JOVIANS

Planet of Origin: Jupiter

The Jovians are a sentient species that built several advanced arrogant civilisations on their planet which, given the size of the planet, have not all made contact with one another. Although  their technical science is on pair with that of Humanity, their knowledge of astronomy is lcose to nil, as they know about the existence of the sun and the four Galilean moons of Jupiter, but are ignorant over all other celestial bodies.

They are built around radial symmetry with  tentacles and sensory organs allowing them to detect mass. Substances of low specific mass are transparent to them, allowing to see through the dense Jovian atmosphere as well as Humans see through Earth air. Oxygen is lethal to them, and they may drown if submerged in ammonia, which is known to form lakes in the vast islands where they built their cities. 

For 25 years they had radio contact with Human settlers on Ganymede, but immediately cut contact when they realized  they were dealing with non-Jovians, feeling sudden repulsion and xenophobia. Robots were later sent down to the planet in hopes of restoring contact.

Source: Isaac Asimov, Not Final! (1941), Victory Unintentional (1942) 

VENUSIANS / IT CONQUERED THE WORLD / ALIEN

"There's only one on Earth. They're nine altogether. The other eight are still on Venus. They're the sole survivors of a race that was born too soon. It developed in the eruptions and the boiling gases of Venus, a planet that won't catch up to Earth in perhaps a million years in climate."

―Dr. Tom Anderson

It remains unclear if the so-called venusians are indeed coming from the planet Venus as the only source we have on the subject is Dr Tom Anderson who was lied to abondantly by the creature. As of the mid 20th century they are practically extinct, with only nine remaining individuals, one of which, after having established radio contact with Anderson,convinced him of its benevolent intentions,  hijacked an Earth satellite to land on the planet in an attempt to conquer it with the scientist's help. Anderson believed that the alien, with its mind control abilities  would make humans emotionless, and therefore free them from war and misery. 
The creatures are ruthless and highly intelligent and have developed an advanced civilisation which is now extinct. They are the shape of a cone separated in eight soft ridges going from their top to their bottom, and at the base of which stick out six short frills or tendrils per ridge which likely aid in locomotion. On each side of their body come out two arms with crab-like pincer hands come out. They have a caricatural face on its front with a large mouth filled with sharp pointy teeth, the canines being tusk-like, deep set eyes and a embryonary nose. At the top of their body protrude a pair of short horns or antennae with which they can communicate with the small, manta-ray like flying probe creatures they can release from the base of their bodies. These flying organisms seek targets and bite them on the neck, releasing a small spike that allows the Venusian to control the victims' nervous centers from distance. Apart from their mind control abilities, the Venusians also have the ability to neutralise most types of technological devices within a large area around them.

Source:  It Conquered the World (1956) by Roger Corman

MARTIANS / IT THE TERROR FROM BEYOND SPACE

Planet of origin: Mars

This martian creature is a savage and possibly non-sentient humanoid reptilian species which nurrishes itself with the fluids of other creatures, preferably animal, sucking them dry. Standing two meters tall,  It has large three fingers hands and a large mouth with big pointy teeth. To survive the martian environment, it has developed a remarkable strenght and endurance, its thick scaly skin protecting it from most kinetic harm.

Contact was made with one of these creature in 1973 when a first manned mission to the red planet was decimated with only one survivor who was resued by another expedition aboard which ship a creature was able to stow away, killing part of the crew before they managed to throw it out the airlock.

Source: It! The Terror from Beyond Space is an independently made 1958 black and white science fiction film directed by Edward L. Cahn and written by Jerome Bixby.

SAUCER MEN / MONSTERS / LITTLE GREEN MEN / HELL CREATURES

The saucer men are a green skinned humanoid species which developed a space faring civilisation. With have shorter limbs than humans but heads about four times the size of that of a human for, they stand at a height of about four feet. They have pointy ears huge bulgeous eyes about size of a fist and heavy lipped wide mouth with sharp pointy teeth. Huge veins are apparent through their skin. 

They are very light sensitive as sudde exposure to bright violent lights can not only blind them but cause them extreme pain as blood rushes toward their eyes which, brought to extreme levels can cause their death due to hemorragical explosions.

Their hands have four long fingers equipped with retractable needle-like hollow claws which can inject hugh doses of pure alcohol, enough to kill subjects as large as cattle and have an additionnal eye on their backs. As these hands are also detachable and able to move around and make rational decisions even after their owner's death, it remains unknown if the aliens are able to transfer at least part of their consciousness in them as some sort of lifeboat or even if the hands are distinct entities which operates in symbiosis with their user.

The Saucer Men are known to have briefly visited Earth's eastern coast of northern America, near Hicksburg, during a June night of 1957 but their visit ended up in disaster with the death of the whole party.

Source: Invasion of the Saucer Men (also known as Invasion of the Hell Creatures, working title - Spacemen Saturday Night) is a 1957 sci-fi comedy filmby Edward Cahn, written by Paul W. Fairman (original story), Robert J. Gurney Jr. and Al Martin

The needle-like claws of the alien extended.

 

The severed hand moving on its own.

 The alien's spaceship 

 

 

PLAN 9 ALIENS / GRAVE ROBBERS FROM OUTER SPACE

Planet of Origin: Unknown

The plan 9 aliens are a humanoid species, looking almost undiscernable from normal humans, who have developed an advanced spacefaring civilisation, generally peaceful but ready to eradicate species which the predict might become a threat before they do. They travel through space using saucer-shaped ships equipped with heavy force field and operate from a network of at least 7 space stations.

They are known to have visited Earth in 1959 to study mankind and make contact with the planet's leaders. Their attempt was met with fear: as soon as their flying saucers were sighted in the sky over the united states of America, mainly Washington and California, they were greeted by heavy fire from the army. 

To force mankind to better dispositions, they decided to use Plan 9, which consist of using a technology allowing the resurrection of the recently dead by stimulating their pituitary and pineal gland with remote controlled electrodes and using them to create an army of zombies. 

After interviewing some humans, the judged the species dangerous as their development was putting them on a track to develop solarbonite, a substance capable of  "exploding sunlight molecules" (photons?) which they would be too immature to have at their disposition: "It is capable of exploding the particles that make up sunlight itself.  If contained in a weapon, it can set off a chain reaction that explodes sunlight,  along with anything the exploding sunlight touches, that will eventually destroy the universe, possibly at the speed of light itself."

The aliens ruled that mankind should be destroyed to prevent this from happening. Luckily, the humans they got in contact with managed to thwart their effort and the alien ship exploded while leaving the planet.

Source: Plan 9 from Outer Space, by  Ed Wood Jr.

Alien space station 7

Alien saucer over California.

ROBOT MONSTER / RO-MAN / RO-MEN

Planet of origin: Ro-world

Ro-men are humanoids who developed an advanced spacefaring totalitaristic civilisation which, despite claiming to be coldly logical, often exhibits brutish and flawed behaviors.

Because of their name, the Ro-men are believed to be at least partly cybernetic, but this remains undocumented. Physically, they appear like 2 meters tall humanoid with a body ressembling that of a fully bipedal gorilla with a spacesuit helmet. It is unlnown if their furry body is their natural one, part of a suit or whatever else and if what looks like an helmet is actually one.

Under the management of a Ro-Men designed as the Great Guidance, they are known to send agents by teleporters to planets they wish to conquer to perform the extermination of the dominant species. Such an attempt is thought to have been tried in the 1950ies on Earth but somehow failed, maybe due to the premonitory dream of a human boy who foresaw the whole invasion as it might have occured.

They possess incredible technologies (shown on the pictures next to the alien) such as:

• Interstellar range teleporters they use for instantaneous travel to other worlds
• Interstellar comunications devices, they use to communicate with agents on other worlds, 
• The calcinator ray , a discriminative weapon able to eradicate a given type of lifeform on a planetary scale,
• The Cosmic Q-Waves, a timescooping device able to bring creatures from the distant past in the present (such as dinosaurs)
• The Cyclotronic vibratior does cyclotronic vibrations which can supposedly smash a planet out of the universe but which can also create violent earthquakes on a global scale.

Source: Robot Monster, by Wyott Ordung and Phil Tucker

LAMBERJ

A non-corporeal energy-based species which has developed a space faring civilisation and is most likely energy-based like the Mizzaretts with whoe they  have a commercial rivality with the Lamberj species.

Source: Isaac Asimov, Buy Jupiter!

MIZZARETTS

A non-corporeal energy-based species which inhabits inhabit the coronal haloes of O-spectra

stars and has developed a space faring civilisation, travelling the cosmos in field-enclosure ships. When encountering corporeal species, they usually use encounter suits aka Simulacrons which are tailored to look like a divine or idealised version of the species they interact with. When meeting humans, they look like golden greek gods, but act very mundanely.

Mizzarett have a commercial rivality with the Lamberj species. They are known to have colonies on Kimmonoshek.

Source: Isaac Asimov, Buy Jupiter!

NEPTUNIANS

Planet of Origin: Neptune

Neptunians are a green skinned reptilian humanoid species supposedly native to the planet Neptune or one of its moons.They are amphibious with four fingers palmed hands and feet, have large yellow eyes on each sides of their head whihc gives them an excellent line of sight. Their body is covered in scales. Although their level of civilisation still remains unknown, they are known to have developed sewing craft as their use of clothing demonstrates.

Note: In 1975, the Mego toy company produced the so-called action figure doll as part of their Star Trek aliens toy line although such a creature never appeared at any time inside the  franchise.

Source: Mego Star Trek toyline. 

KLOROS

The Kloros are a chlorine-breathing, colonial insectoid species which developed an expansionnist space faring civilisation. They resemble man-size insects with a number of small tentacles protruding from their chest, a long, slender neck and a diminutive head containing a somewhat triangular-shaped proboscis and a pair of huge bug eyes. Their central nervous system brain is located in the abdominal region, and their head acts mainly as a support for the sensory organs. Their blood is green. Oxygen is deadly for them.

Kloros  have a respectable sense of morale. They lack the concept of familial bond, but do have an analogous "group bond" to their colony and always travel with their groups.

Source: Isaac Asimov, C-Chute (first published in the pulp sci-fi magazine Galaxy in 1951 and  later published in the book Nightfall and Other Stories).

MAUVS / MAUVIANS

The Mauvs are a large humanoid species which developed an industrial civilisation that ended  in a nuclear war. The survivors were rescued by the Hurrians who had bee nmonitoring them. They helped them rebuild their world, instituting a eugenics selection program to make the Mauvian species more docile. The Mauv were unable to pay for the Hurrians' service as their world had been rendered resourceless by the war and the whole species, forced to pay in servitude, rather than material goods, became slaves to the Hurrians.

The Mauvs have thinly-haired bodies, coarse-featured faces, broad noses and flat cheekbones. There appearance contrasts with their submissive nature, as they never question authority, and never disobey orders from the Hurrians.

Source: Isaac Asimov, The Gentle Vultures, by Isaac Asimov (1957)

HURRIANS

Planet of Origin: Hurria

The Hurrians are a sentient species which had developed a non-competitive interstellar empire as of the late 19th century. 

They generally look like an Earth's monkeys, with long thin arms and stubby tails, standing about a meter tall, with black skin covered in dense fur, and a mobile nose on their faces. They evolved from small primates, rather than apes, are vegetarian and mostly non-competitive. They abhor the idea of violence and war, and have accepted as fact that all other species end up destroying their own civilizations after discovering nuclear power. Thus, rather  trying to interfere in their warfare or prevent them. they developed a policy of monitoring other civilizations from distance, waiting  to come down and help the survivors build a new civilization, genetically altering them to remove their competitive impulses and making them subjects to the Hurrian empire.

Although they describe these actions as righteous and helpful, the Hurrians benefit of the removal of competition which ensures their status as the dominant power of the galaxy and make each species pay for the help received in one form or another.  They are known to have aided the Mauvs in such a manner. 

Source:  Isaac Asimov, The Gentle Vultures(1957)

VENUSIANS / PHIBS / CENTOSAURS

Planet of origin: Venus

Phibs are a peaceful green skinned amphibian humanoid species with wide set goggle eyes, broad lipless and mouth, muscular webbed arms living in apreinustrial tribal society in the highlands lakes of Venus.  They communicate via touch-based telepathy and  suckle their own. They have been known to take momentary telepathic control of less evolved indigenous lifeforms such as the twenty-legged two hundred tons serpentine bodied monsters called centosaurs for self-defense.

Note: Phibs look much like the version of the venusians Frank R. Paul's Painted the same year.

Source: Isaac Asimov, Half-breeds on Venus.

MARTIANS / TWEENIES / HALF-BREEDS

Planet of Origin: Mars

Martians are a humanoid species living on Mars which is genetically and socially compatible with Earth's humans but which possess "cold, analytical reasoning powers" but lack the "emotional drive and boundless energy of the Earthman". 

After mankind began to travel to the red planet, tweenies - Half-human half-martians half-breeds - started being born (see picture). Thet weren't accepted on Mars and so had to be brought back to Earth where they were being taken care of by social services. mainly in asylums. Tweenies are generally more intelligent than humans or martians but look like normal humans with a "brush of wiry, dead-white hair that rose stiffly in all directions like porcupine-quills".

Note: Martians are actually never met in the stories conerning Tweenies but are believed to be human-looking as the stories tell of more than a thousand tweenies are known to have been born, so inter-species unions must have been somehow not against nature, although no details are given on that matter.

Source: Isaac Asimov, The Half-Breed, Half-Breeds on Venus