Alien invasion of planet Earth

Alien Queen Egg

Ovomorph Ovomorph main article The Ovomorph[19] (in Spanish: Ovomorfo), also known as the Alien Egg,[20] Egg,[21] Alien Ovoid,[22] Egg Chamber[23] or Xenomorph Egg,[7] is an egg-like organic capsule containing a Facehugger, generally considered to be the first stage in the life cycle of the Xenomorph species. They measure 1 meter tall,[7] 46 centimeters long,[7] and weigh approximately 27 kilograms,[24] and are produced and laid by a queen in a hive or a Yautja clan ship and later placed on a Sucker Ship that will release the eggs on different planets to prepare a hunting ground for the young Yautja. Research indicates that Ovomorphs can remain viable for hundreds of years.[25] When an Ovomorph is in a state of hyperfertility, there is a high chance that there are two Facehuggers inside it, not just one.[26] The Ovomorph contains within it a fluid mixture of enzymes, hormones, and proteins, protected by a membrane, which nourishes the Facehugger during its dormant period.[7] Ovomorphs are distinguished by having dark brown, tan, or grey coloration patterns.[7] In the absence of a Queen, isolated genetic changes will occur, resulting in the ability for the lone Drone or Warrior Xenomorph to produce eggs from other organisms,[7] something the Drone did at Weyland-Yutani & the Colonial Marines' Golgotha ​​training station, using the bodies of Marines and Yautja to form new cocoons.[27]

Facehugger

The Facehugger[26][28] appears as a pair of long fingers attached to a long spiny tail with two fleshy sacs forming the rest of the body. Measuring one metre in length, they coil inside its ovomorph. They lie curled up inside their ovomorph (alien egg) until disturbed. When the egg's top flaps break off, a Facehugger will lunge toward the unsuspecting victim, using its fingers to grab and hold the would-be host's head. It will then wrap its tail around the throat, ensuring it stays in place long enough to deposit its egg via a long proboscis that it feeds into the creature's esophagus. Praetorian Facehugger The Praetorian Facehugger[21] is a larger, more armored version of the classic Facehugger that produces Praetorians regardless of the type of host it impregnates. It is more durable, has a greater reach, and can jump farther than the regular Facehugger.

Chestburster

The Chestburster[29] or Chest Buster[23], also known as the Embryo[7] or Stage 2 Xenomorph,[7] is known to be the third phase of any Xenomorph's life cycle.[30] Once inside the host, it attaches itself to the internal organs and feeds until it is satiated, gaining essential nutrients for its development.[31] Its gestation is quite rapid, being able to grow rapidly within the safety of the host, assimilating new genetic material as it matures.[31] Having inhabited the host's body, the Chestburster mutates several times like a reptile, due to its hyper-efficient metabolism causing rapid growth towards its final adult form, the Xenomorph.[31] Despite being small, the Chestburster's jaws are strong enough to slice through human flesh and bone as it tries to burst its chest and exit the host. Similarly, they are characterized by emitting quite high-pitched sounds.[15] At this stage they have skin quite similar to that of humans in terms of texture,[7] although the pale color and size will always depend on the type of host and it has a weight of 4 kilograms.[7] When a baby Xenomorph emerges from its host's belly, it is known as a Bellyburster, although that name is not official.

Drone

The Drone[32], also known as the Worker Bee[21], Infant[33] or mistakenly Warrior Alien, is the most basic of all the hive xenomorph creatures, resembling a worker bee. They are responsible for building the hives through the use of a strong resin-like material they secrete. Spawned from human hosts, they stand approximately two meters tall and have smooth, elongated heads. As they age and mature, the smooth shell falls off, revealing the ridged structures that adult Warriors have. Another job of the Drones is to obtain captives for the hive to birth more xenomorphs, although this is also the job of a Warrior. In combat, they are able to wield their long tails with deadly accuracy, and the sharp spikes can pierce marine combat armor. Like other evolutions, they are also capable of spitting acid at their enemies, and can do so with great skill. Drones typically work alone, using stealth and waiting in ambush to attack their prey. Their jet-black exo-skeleton allows them to blend into their surroundings, oddly fitting among the pipes and alcoves of starships. When working together, a pack of them will often force their prey straight into an ambush by chasing them around. The Drone can develop an acidic foam filled with cysts that it spits at potential hosts. The cyst invades the body through the resulting acid-induced wounds, causing tumors that utilize the host's body to generate multiple nutrients beneficial to the development of the growing Chestbuster.[21]

Alien Warrior

The Alien Warrior (English:Xenomorph Warrior), also known as the Alien Soldier,[34] mistakenly the Drone or simply Warrior,[21][35] is the most numerous of all the Alien Castes and one of the most aggressive in existence. The most recognizable form of them is the one spawned from a human host.[21] Standing two meters tall and highly agile, they walk on two legs but can often move with blinding speed if on all fours. They can be identified by their elegant, elongated head, covered in rows of ridges, and the set of four dorsal tubes on their back. A Warrior's agility allows it to scale sheer walls with ease, quickly navigate through narrow pipes and tunnels, and leap across chasms and long distances as if it were traveling on the ground. They are also strong, able to lift a synthetic off the ground and split it in half with little effort. Like many Xenomorphs, they will use their strong skulls to slam into enemies and doors. A Warrior will sometimes even use its whip-like tail to knock an enemy off balance before finishing them off with a swipe of its claws or a bite of its secondary teeth. Warrior Xenomorphs also seem to ignore pain inflicted upon them, as they have been seen to fight even with missing limbs or gaping holes in their bodies. Even in death they can kill, as weapons that inflict heavy trauma on them cause their pressurized blood to explode, raining acid down on anything within range. It should also be noted that flamethrowers seem to cause the same effect and should be used with caution against these creatures and while many marines believe them to be dumb animals, Warriors possess a great capacity for learning and adaptation. They will use stealth tactics to ambush their targets, flank their opponents from multiple angles (even from above) and attack them with a vengeance.

It should also be noted that flamethrowers appear to have the same effect and should be used with caution against these creatures, and while many Marines believe them to be dumb animals, Warriors possess a great capacity for learning and adaptation. They will use stealth tactics to ambush their targets, flank their opponents from multiple angles (including from above and below), and even sacrifice one of their own to engage an enemy who thought they were safe. There are variants among the Warriors' heads, as the Warriors that settled in Gunnison had a much more detailed head with more prominent scales compared to other Warriors from other hives.

Warrior Evolved

A Warrior will mutate into a unique type of its own. Highly adaptable, these creatures are often mistaken for a standard Warrior until it's too late for their enemies. Some are able to spray acid at close range on multiple enemies at once, others can camouflage their exoskeleton to blend into their surroundings and jump on their enemies, and some of them are even able to heal the most grievous wounds almost instantly. Classified as Evolved Warriors, the company's scientists believe that they are an evolutionary dead end and that once their metamorphosis is complete, they will not change any further. It is theorized that their evolution is due to an immediate need required by the hive, but not as a long-term creation. Whatever the reasoning behind these monsters, they must be encountered with extreme caution, as each one is different and there is no way to determine what capabilities it has until it has displayed them.

Royal Guard

The Royal Guard, also known as the Body Guard, is a Xenomorph that serves as the guardian of the Hive Queen, rarely venturing far from the hive, something that is more common in castes such as the Warriors. Royal Guards are much larger than a Warrior, and are among the most powerful of all the castes, being one of the later evolutions of the Xenomorph life cycle, these creatures are far more intelligent and cunning than typical Xenomorphs. The most distinctive feature they possess is that of a large crest on their head, similar to that of a Queen, however, they lack the extra set of arms that a Queen has. They are typically dark in color, ranging from ebony to blue-black. Their armored skin is nearly bulletproof, and they are able to continue fighting where lesser Xenomorphs would have been cut down. Though they dwarf the smaller members of their species, they are nearly as fast and agile as them, as well as being immensely stronger.[37] While exceptionally intelligent and cunning, they often consider it largely unnecessary and can simply take on most enemies. They are noted for having long claws that can tear through armor as if it were paper, and their long, bladed tails can shred through even the toughest Yautja's defenses.[37] At range, they can spit large amounts of acid, making them a deadly foe at any distance.[37] Sometimes, several Royal Guards simultaneously evolve to become Praetorians and the strongest of them will go on to become the Queen.

The Praetorian[21][39] is a xenomorph caste that comes into prominence when a new hive emerges, or when a queen has been killed. A new teenage queen evolves from the Royal Guard. Often called a Praetorian, at this stage of mutation the creature is stronger and faster than a Royal Guard, but less destructive than a fully transformed Queen. Sometimes, several Warriors evolve simultaneously to become Praetorians, and the strongest of them will go on to become the Queen of the hive. Queen The Alien Queen, also known as the Bug Queen,[40] Monster Queen,[41] Demon Mother,[11] or simply Queen,[21][42] is one of the larger forms of the Xenomorph species who serves as the mother and leader of a hive of Xenomorphs.

At the head of an entire hive of Xenomorphs, the Queen is the center around which all other castes revolve. She has a superior intellect and is much larger in size than standard Warriors, with an extra pair of arms protruding from her chest and a larger head crest emerging from the back of her skull. Though more than capable of taking on almost any foe in hand-to-hand combat, the Queen tends to leave that to the lower-ranking Xenomorphs. Instead, she most often finds herself at the heart of the hive, attached to a massive sac, laying the enormous nests of eggs that contain the Facehuggers, the tiny aliens that propagate the species. Unable to move, the Queen must rely primarily on her royal guards for protection should she be attacked, however, the egg sac can be painfully torn off should she need to escape or is forced to face her enemies directly. Queens have very thick, crown-like plates on their heads that they can bury their face in for protection. This large shell makes her look ungainly and unbalanced, as it is disproportionate to the rest of her body. However, this is an illusion, as she can move with great agility, and one theory is that the extremely long, spiked tail helps to compensate for this. She also has double-jointed hind legs, allowing her to reach speeds that such a large animal could not possibly achieve. The Queen's tail is strong enough to throw a Yautja over the edge and even split them in half using its strength.

With thick armor plates and a size easily twice that of a normal Warrior, the Queen can withstand most small arms fire, as well as possessing the fortitude to withstand fire for short periods of time. Her strength has also been magnified, and she can easily slice a synthetic in half with her massive claws. Even a fully Blooded yautja is more than likely to perish if they attempt to go toe-to-toe with a Queen. Yeyinde had a Trophy Wall on Yautja Prime with several Alien Queen skulls and for the Yautja this is a sign of honor and bravery, something that the females really liked.

Hive Mother

When a hive reaches a massive number of Xenomorphs inhabiting it, a Queen will often become what is known as a Hive Mother or Queen Mother. The ultimate transformation of the Xenomorph species, this creature is capable of controlling a world-wide population of Xenomorphs. With a head larger than an industrial loader, claws capable of splitting an M577 in half, and a tail with a hardened, wide tip. This beast is the most cunning and dangerous of its kind. Only a handful of such monsters are known to exist, and to the Yautja, they are the ultimate prize, and entire clans have perished in pursuit of these near-mythical aliens.[44] Hive Mothers command legions of Royal Guard and thousands of warriors, and an unlimited number of drones and other creatures.