Zetan aliens

Zetans  are an extraterrestrial humanoid species.

Background
The origins and background of the zetans are largely unknown, but it has been observed that they use their ability of space travel to study other planets and species, including humanity. They use at least two motherships to study the Earth, one known as "Zeta" and an unnamed one), they have been visiting Earth since at least the time of feudal Japan, given the fact that one of its abductees is a samurai. Before and after the Great War, they abducted humans and various items created by them, as well as other creatures such as super mutants and brahmin, for study.

Despite the length of their study, zetans remained unknown to humanity at large for the vast majority of their visitation. It was not until the abduction of Colonel Hartigan and the Clarabella 7 capsule that their influence became felt by modern society, with groups such as Quaere Verum formed to reveal the truth about them. Their technology may have been used to create the MPLX Novasurge, a prototype plasma pistol recovered by Quaere Verum, that was later recovered by the zetans themselves.

Biology
Zetans are diminutive, hairless, yellowish-green-skinned humanoids with short, wiry limbs and green blood. Their heads are disproportionately large, with round, heavy-lidded, solid black eyeballs with no discernible iris or pupil; a thin, toothless mouth with green tongue, and two pairs of small holes where ears and nostrils would be. Aliens have no opposable thumbs, each hand having three long, tentacle-like fingers with large suction cups at each fingertip that allow them to manipulate objects. They breathe a similar atmosphere to humans, and (at least those on Mothership Zeta) subsist mainly on a diet of strange alien worms and squid.

Organization
The zetans seem to have a strict society focused on work and progress, with no apparent concern for hobbies and personal pursuits. Their architecture is spartan and purely functional; for instance, their beds (called stasis chambers) are sterile metal capsules with no mattress, blankets, sheets or other pieces of bedclothes typically found in a normal human bed, and no discernible means of entertainment can be seen aboard Zeta. However, the aliens, in their own right, appear to have some degree of emotion since alien workers display obvious fear when confronted with armed assailants. In another case, the aliens are shown to have a fascination with Giddyup Buttercup, as demonstrated in a captive recorded log onboard Zeta, of Sally being taken to the recording room and noticing a Giddyup Buttercup. She notes that upon her calling attention to it, the aliens become very excited, though she has no idea why they act this way.

They view other species as laboratory animals, worthy of preservation and storage at best and vivisection and experimentation at worst. They speak in their own language of high-pitched screeches and wails. As such, verbal communication between humans and aliens is impossible. This isn't helped by the fact that, barring recording some brief biographical information, the aliens simply aren't interested in discussion.

They are incredibly advanced in their variegated technological fields, capable of spaceflight and technological feats equal to but often beyond that of even the most advanced human pre-War technology. They also possess technical faculties such as long-term cryostasis, powerful rayguns, genetic engineering, teleportation and holograms. However, they are totally dependent on technology and are physically limited by their extreme use of it. Because of this, they are physically fragile, lacking in raw strength, are ineffectual in melee-based combat and don't possess especially protective armor and clothing.

Aliens typically wear spacesuits, the color of the suit apparently indicating rank, and soldiers generally carry shock batons, disintegrators and atomizers. They prefer to attack their foes in large numbers and tend to have guardian drones with them.

Military
Due to their frail bodies, the zetans aboard Zeta generally rely on guardian drones to do most of their fighting. However, certain zetans will utilize personal shields and rifles, indicating that there are combat-ready members among their ranks. The most powerful known weapon in their arsenal is the death ray underneath their ship.

Aliens typically wear spacesuits, the color of the suit apparently indicating rank, and soldiers generally carry shock batons, disintegrators and atomizers. They prefer to attack their foes in large numbers and tend to have guardian drones with them.

Teleportation


Similar to the the Institute's Molecular Relay, the crew of Mothership Zeta possess a series of teleporters known as a teleportation matrix. They allow access between areas of the ship, as well as to and from beacons that can be deployed to the surfaces of planets.

Cryoscience
Zetans possess an advanced understanding of cryostasis, to the point they maintain a specialized cryo lab aboard Zeta dedicated to keeping their various abducted subjects stored between experimentation and interviews. This storage was seemingly capable of keeping its subjects alive healthily for centuries, though it was not without risk. Under certain conditions, it can lead to the subject expiring upon being thawed. Colonel Hartigan became a victim of such conditions upon being thawed by the Lone Wanderer.

Holography


Zetans utilize holographic technology, similar to both Big MT and National Electric.

Robots and computers

 * Experimental weapons drone - experimental security robot armed with a drone cannon Ex-B
 * Guardian drone - security robot armed with a drone cannon.
 * Support drone - maintenance robot.

Vehicles

 * Flying saucer - small ship with a saucer-shaped body used for fast operations that house two pilots. The only known flying saucer is the one that crashed in California.
 * Mothership - large ship dedicated to long-term space travel and study species. It's generally located in space. It houses an entire crew of aliens and is commanded by a captain. The overall shape of the ship resembles a colossal saucer with another small disc-shaped section attached to the bottom. Known motherships are Zeta and the unnamed mothership comes right after the Zeta bridge is captured by the Lone Wanderer.
 * Recon craft - small ship with a disc-shaped rear body used for stealth operations that house only one pilot. Known recon craft are Theta, another unnamed craft that exploded in mid-air in the Firelance event, and another unnamed craft hovering in the Mojave Wasteland if Wild Wasteland is taken.
 * Unnamed Spacecraft - A small, single pilot ship is found at the UFO crash site within The Commonwealth between Beantown Brewery and Vault 81. The pilot survives the crash and relocates to a nearby cave.

Medical



 * Abominations - biological weapons created from humans with aliens DNA.
 * Alien biogel - ingestible curative gelatin-like liquid and accelerate organic tissue's regeneration processes gel.
 * Healing archway - care generator restoring health, removing all radiation, clearing any drug addiction and restoring crippled limbs.

Food

 * Alien squid food - A strange squid-like creature with long-term conservation.
 * Alien worm food - A strange worm-like creature with long-term conservation.

Device

 * Alien epoxy - Advanced liquid repairing agent.
 * Alien homing beacon - Beacon teleportation sent by a mothership to return quickly.
 * Drone control device - Remote control for alien drones.
 * Force field generator - Portable forcefield used for protective cover or blocking a passage.
 * Inertia suppression field - Personal protection shield technology.

Miscellaneous

 * See alien items

Appearances
Zetan aliens appear in Fallout 3, its add-on Mothership Zeta, Fallout: New Vegas, Fallout 4 and Fallout 76.