Facehugger (Earth-7149)

"Woke up gagging on a creature — like a spider. It wrapped around my face."

- - Larry Purvis

The Facehugger is one of the forms of the xenomorph endoparasitoids, being the second stage of its life cycle, hatching from an Ovomorph. It is extremely short-lived, and exists merely to implant a Chestburster within a potential host through the victim's mouth. Beyond its acid spit, a Facehugger has no real offensive capability other than aggressively jumping towards its prey, using both stealth and immobilization of the victim to implant the Chestbuster. After a Facehugger implants the Chestburster, it dies shortly after.

Anatomy and physiology
"Looks like some kind of scorpion..."

- - Thomas Kane Facehuggers resemble a pair of skeleton-like hands fused together, with a tail that resembles a spine, or a scorpion. The creature has eight finger-like long legs that allow it to move at incredibly fast speeds, as well as a tail adapted for leaping. This gives them an appearance similar to that of Earth's Chelicerata arthropod subdivision, such as arachnids and horseshoe crabs. Beneath the Facehugger lies it orifice, which they use to impregnate their victims with Chestbursters, largely resembling a female human's vagina. They height 3 feet, from the tip of their tail to the tip of their digits.

The lower digits of a Facehugger grants them the ability to move quickly through any surface, from the ground to walls, as well as its capability of "gripping" the head of a host so it can implant its Chestbuster. Despite being rather skinny in appearance, the digits are strong, and are known to tear the skin from skulls. Once the creature is able to grip around the head of its host, removal is nearly impossible and impregnation is almost a guarantee, unless the victim is physically strong enough to remove it. As such, species such as humans and other hosts are not able to escape implantation. A Facehugger can also use its tail to strangle their hosts when they attempt to remove them, which leads to many deaths before the impregnation even begins. Much like other xenomorphs, their blood is acidic green, and can severely wound a victim or anyone who attempts to attack them. They are beige in color, differently from their usually all-black xenomorph brethren.

At the base of its tail lies a pair of bag-like bladders which they use to circulate air to the lungs of its victims during the impregnation process. From the Facehugger's orifice there is a lengthy proboscis, which they extend to their host's mouth in order to implant the Chestbuster. Despite being mostly useless in combat, the Facehugger's fast movements and swarm tactics can make them deadly in large numbers and difficult to kill. They can also be employed in combat roles.

While living within their Ovomorphs, Facehuggers are lifeless and inert. As soon as the Ovomorph detect a living sentient being approaching, it transfers its last bio-electric waves to the Facehugger, which then becomes "alive" and attempts to launch itself to the host. Once they leave the Ovomorph, Facehuggers uses a set of thermoauditory senses to track down their prey. Initially, during the xenomorphs' Feral Stage, Facehuggers instinctively act out of curiosity and desire for survival, and will not stop until they are either able to impregnate a host or be killed by them. However, once the xenomorphs reach the Coordinated Stage, Facehuggers are mass-produced by Queen to impregnate hosts and be supported by other xenomorph variants. They can survive for 120 hours outside of their Ovomorphs without implanting a Chestbuster. Facehuggers are not stopped if their host is either killed by them or dead beforehand.

Submerged or stored Facehuggers can still carry out their impregnation, as seen by the xenomorph specimens stored by the Weyland-Yutani Corporation on Hadley's Hope, Aegis VII.

Subduing hosts
"My wife... she got one of those things on her face."

- - The recordings of an unknown citizen of Freyja's Prospect

As soon as a Facehugger detects its potential host, it will leap with aggression to their faces, wrap its tail around the host's neck, and implant its digits around the skull. When the creature notices it can safely carry on the impregnation process, it renders the victim unconscious through a cyanose-based chemical with paralytic properties that is spread during skin contact between the Facehugger and the host. Its delivery mechanism is composed of dimethyl sulfoxide (DMSO), which becomes extremely effective in rendering adult members of any species in comatose. It is theorized that the Facehugger is able to determine the composition and body mass of its host, and when it does so, it can chemically suppress their immune system during the impregnation process in order to prevent the host's defense systems of counterattacking the Chestbuster, which is embryonic. This is seemingly the result of a substance similar to azathioprine.

Facehuggers will also use their long tail to suppress the host by wrapping it around their throats and asphyxiate them. This method, while brutal and efficient, is rarely employed by the xenomorphs duo to being too slow. During their impregnation process, the victims of the Facehuggers experience distressing and vivid nightmares, which can seemingly be explained by the xenomorphs' poorly understood psychic abilities.

Impregnation process
Once the Facehugger attaches itself to the host, it inserts the proboscis down to the victims's throat, which supplies them with a suitable atmosphere for continuous breathing, as well as the implantation of the xenomorph embryo into the victim's esophagus. The process wildly vary in time, ranging from several hours during the Feral Stage to mere minutes during the Coordinated Stage and beyond.

In fact, Facehuggers do not literally implant an embryo within their host, instead depositing a tumor at the chest cavity of the host, which consists of a series of tailored cancers that restructure the cells of the host, assembling a Chestbuster. The implantation, much like the process, can vary in time, from a few hours to several minutes depending on the xenomorph stages and evolution. During the Feral Stage, it is theorized that the Facehugger detaches itself from its host after receiving a recombinant plasmid pulse from the Chestbuster. In later stages, it is likely that the Queen telepathically commands them to do so.

During the impregnation process, the Facehugger is able to determine the suitable atmosphere required for their host to breathe, as well as provide the necessary mixtures for the host's survival in an otherwise unsuitable to deadly environment; this is the case of the unggoy, who breathe methane, and not oxygen like humans, and the xenomorphs themselves, and so the Facehugger will generate methane to its unggoy host in an oxygen-filled environment so the victim will not die. The same case happened with Thomas Kane, who was attacked by a Facehugger in the methane-rich LV-423, where the creature breached his IRC Mk.50 Compression suit's helmet and provided him with oxygen while on the natural satellite.

Alternate forms
Much like the rest of its xenomorph brethren, Facehuggers have a multitude of alternate forms, each with a specific role in mind. Royal Facehuggers are much bigger and stronger than its normal counterparts, but it impregnates its victims in a much slower pace. These Facehuggers are capable of impregnating potential hosts directly with a Queen, and can only be formed when a Queen has been formed, in the latter case for the Queen to create special xenomorphs to assist it.

Removal and defenses
"Surgically removed before embryo implantation. Subject: Marachuk, John J., died during the procedure.' They killed him taking it off."

- - Bishop While Facehuggers can be removed before it impregnates its host with a Chestburster, the process is long, painful, difficult, and potentially fatal for the victim. The Facehugger's many abilities, from grip, to the sedative chemicals and the perils of its acid blood makes a safe removal nearly impossible. If a Facehugger feels threatened from external forces, it kills its host with a volatile chemical overdose or strangulation in an effort to not allow them to survive, which happened with Hadley's Hope inhabitant John Marachuk after ONI scientists attempted to remove the creature. If the Facehugger is killed, it creates a potential fatality for the host thanks to its spilling blood or simply collateral damage. Even during the initial stages of an attack, very few individuals have been recorded to remove the creature.

Conventional USCMC soldiers are largely ineffective against Facehuggers, as they are able to burrow through rubber, polymer, and fabric.

The resurrected Ellen Ripley, aboard the USS Auriga, was able to remove a Facehugger from her face thanks to her partial-xenomorph DNA, possessing enough physical strength that excels that of a baseline human, as well as immunity to the xenomorph's acidic blood.

Replicants are strong enough to pull Facehuggers out, and their nature as non-organic beings allows them to be effectively immune to impregnation.