Andromedan (The Conquest of the Earth)

The Andromedans are a sapient alien species hailing from a terrestrial planet nicknamed Androm, in the Andromeda Galaxy.

Biology
Andromedans have been consistently described as beautiful and exotic creatures. Their bodies are iridescent and conical in shape, and somewhat resemble a mollusk's shell. They also have three tentacle-like arms which can be extended or retracted at will, and are equipped with similarly tentacular digits. On the top of their bodies they have three eyestalks arranged in a triangular formation, and an additional fourth eye at the base which is specialized for seeing in the ultraviolet spectrum.

The eyesight of the Andromedans is highly developed, and they possess the natural ability to magnify objects at will, using their own eyes as telescopes. This superior sight compensates the Andromedan's lack of hearing and allows them to communicate with each other in their sign language, even when separated by great distances or in an environment that Humans would regard as too dark to see properly.

Their estimated weight is about 150 pounds (~ 68 kg). Their bodies are slightly charged with electricity, which produces an uncomfortable sensation in those who are touched by them. They absorb nutrients like plants and require no air, but consume large quantities of water.

In terms of life cycle, they are hermaphrodites, live for millennia, and reproduce by a strange process of budding which culminates in the separation of the newly-formed individual and the subsequent death of the parent. Mature Andromedans form pairs to fertilize each other, and since both parents start to bud, their reproductive process results in the formation of two new individuals, no more and no less. Since this is compensated by the death of the parents, their population remains relatively stable, although their numbers do increase, however slowly.

Although they possess three legs, modern Andromedans are never seen separated from their mobile hovercrafts. Their legs are short and naturally too slow to be useful, so they spend the majority of their existence in their crafts, just like Humans spend the majority of theirs using clothes.

Homeworld
The Andromedans' home planet is very similar to Earth in size and atmosphere, but possesses almost twice the amount of land and half the amount of water; and orbits a star larger than Sol.

Curiously, the planet has no other native species, neither vegetation nor wildlife whatsoever, and the Andromedans are entirely unaware of their evolutionary descend. This might suggest that they have been the only form of life in their environment for so long that they have forgotten their origins, and might not even have originated in the planet they've come to think of as their homeworld.

Culture and society
Andromedans are diligent and completely unaggressive creatures which will only attack in retaliation after being attacked first. However, they have been known to willfully ignore attempts at diplomacy and will colonize planets without the native's consent. Whether due to intentional maliciousness or an alien sense of morality, they show complete disregard for property and will take over the lands without caring about what the natives say. And while they do take care to not cause physical harm to any living thing without provocation, they will retaliate brutally if attacked. Among themselves, they're completely peaceful, and seem to have no internal conflicts.

Andromedans don't wear clothes, but carry their belongings in pouches suspended by silken cords. Individually, they use hovering disks for locomotion, and spend as much time in their disks as humans spend in their clothes. They travel in spherical metallic ships, about 100 meters in diameter. Being completely deaf and mute, they have developed a sign language, and use their telescopic vision to communicate with each other from distance.

They're an old, technologically advanced civilization, which has possessed spacefaring technology for millennia, to the point that their ships take no more than 12 years to cross the unimaginable distance between their galaxy and the Milky Way. On Androm, their population is about six trillions, and the entire planetary surface consists of a single gigantic city.

History
The Andromedans first visited Earth in 1937. In this first visit, they merely observed the planet and interacted very little with humanity before departing. For the next 25 years there was no sign of them, until a huge fleet came to settle on the planet in 1962 and started building cities.

Appearances

 * "The Conquest of the Earth", by Isaac R. Nathanson (1930)