Alien (The Man from Planet X)

This unnamed species of sapient humanoids need a life support system to operate in Earth's atmosphere. They are native to a rogue planet discovered entering the Sol System in 1951 and designated as "Planet X" by astronomers.

Biology
The aliens are humanoids who bear a Human-like body shape, but have notably large and hairless heads, also standing at a somewhat shorter stature than the average Human. Their heads have a perpetually sad or strained expression, unable to be changed, with large, constantly squinting eyes, and mouths that appear perpetually closed, only allowing them to communicate with humming sounds of musical tone. It is unknown how they eat if their mouths cannot open, but it is possible they take in sustenance other than solid food and liquid. The aliens cannot survive in Earth's atmosphere without a sealed suit, although it is unknown what their native atmosphere is comprised of.

Culture and society
Little is known of the alien society. When their planet was on the verge of extinction, they showed willingness to invade other inhabited planets in order to have a place to live, but also appeared to have been willing to peacefully coexist with other species, as they only turned to invasion and mind-control when they met hostility. Alien scouts, while known to first draw their weapons on members of other species, are also known to attempt to communicate with said members of other species if friendly contact is established, using a gesture that involves holding out their hands, although the meaning of the gesture is unknown. Due in part to their expressionless faces, aliens rarely display emotions, and are known to simply stand stoically when being addressed. As mathematics are a universal constant, and the aliens have a more advanced understanding of the concept than Humans, they are able to communicate with members of other species through mathematics.

Technology
Aliens have technology more advanced than Earth's, including interplanetary spacecraft and anti-gravity technology capable of moving entire planets. Alien spacecrafts, meant for one occupant, consist of a spherical main body with three landing gear legs on its underside and a cone protruding from its top, like the tip of a rocket. The main body has some portholes that can open up, a satellite dish shaped like target symbol, and interior lighting that pulses sickly green. Their spacecraft can also serve as the control and anchor point for alien teletransports, which can teleport entire armies between planets. Alien atmospheric probes utilize a propellant similar to Earth's rocket fuel, with the probes themselves shaped like tiny rockets.

Alien spacecraft hulls are made from a material far stronger than steel, but 50 times lighter, and the glass in spacecraft portholes is far tougher than any Human-made glass, unable to be cut by diamond, although military explosives are still capable of destroying alien crafts. Alien spacesuits consist of a dark flexible body suit with an armored torso, with a large, round, clear fishbowl-like helmet. In the front of the helmet, in front of the wearer's mouth and nose, is a tube connecting the helmet to air tanks on the wearer's backs, the airflow being regulated by a valve on the aliens' left shoulder. Also on the helmet is a black device connected to an antennae, presumably for communications and also connected via wires to headphone-like earpieces the aliens wear. On the chest of the wearers is a large, rectangular device of unknown function bears a circular light on its center, and also serves as a holster for alien pistols, which are connected to the device with a wire, possibly for power. Said alien pistols have a long, thin barrel, and have never been seen in use by Humans, so their destructive capabilities are unknown. Alien spacecraft also carry a device on them that is capable of firing energy beams that can mind-control other beings, such as Humans, making them entirely subservient to all commands given to them, although the effect wears off after a few hours if not reapplied.

History
As it turns out, the aliens' homeworld was slowly dying out, leading them to develop an anti-gravitational system to move the entire planet out of its native star system and into the Sol System. This same technology is what allowed the planet to safely approach Earth without disturbing its orbit, moving it to a distance suitable for the teletransportation of an invasion army. A single alien agent was sent first, piloting a conventional spacecraft that landed in a small village in Scotland.

The alien was armed with the ability (either natural or technological) to hypnotize Humans in order to use them as laborers to construct a teletransport device, which would beam the remaining invaders to Earth as soon as Planet X makes its closest approach. The alien first made contact with scientists Professor Elliot and Dr. Mears, the reporter Lawrence and the professor's daughter Enid. At first, they acted peacefully towards the alien, protecting it from the suspicious villagers and even saving its life when it needed help regulating its spacesuit. However, all attempts at communication failed.

Later, using mathematical equations and music as a common ground, Dr. Mears secretly managed to communicate with the creature, but then violently attacked it and attempted to steal its formula for the material of which the spaceship's hull was made (which had been demonstrated to be tougher than diamond). After escaping from the Professor's house, the alien seemingly became convinced that an aggressive colonization was needed and proceeded to kidnap and hypnotize locals (including Enid, Mears and the Professor) to work on the transport. Lawrence and the townspeople called for military help and managed to evacuate most of the hypnotized workers and kill the alien before the military destroyed its ship and transportation device. When the time came, Planet X passed right through Earth's orbit and back to interstellar space to its next unfortunate destination.

Although the alien's actions are hard to interpret due to its inhuman nature, Enid later speculated that, hadn't Dr. Mears attacked the creature, things could have played out differently.

Appearances

 * The Man From Planet X (1951)