Alien (Battle: Los Angeles)

The Battle: Los Angeles Aliens (hereafter referred to in this article as the "BLAA"), also known by fans as Greys, Chigs, Aquoids, or Landsharks, are a caste-based species who launched a surprise invasion on Earth, most likely motivated by a need for a new home or colony. It is theorized within the film Battle: Los Angeles that they are invading for Earth's liquid water. During the initial invasion, they used an orbital insertion, mistaken for a cluster of meteors, to deploy their forces.

Invasion of Earth
"At 14:46 Pacific Standard Time, twelve different locations across the globe were breached, in what appears to have been a coordinated attack by an unknown enemy. All breaches were along the coastline in what is a campaign of rapid dominance. This is a textbook military invasion. There are massive casualties in New York. Offensive lines are being set up in Boston, and at 13:15 Zulu Time, we lost communications with San Francisco and San Diego. Their status is unknown, but what we do know this: we are the last offensive force on the West Coast. We cannot lose Los Angeles." -- Sergeant Major Glenn Devor in a military news broadcast during the very beginning of the invasion.

During the events of Battle: Los Angeles, the BLAA invade Earth on the 12th of August, 2011. Originally mistaken by the Humans to be clusters of meteors, they are soon revealed to be spacecraft which land off the coastal shorelines of twelve of the world's major population centers. BLAA ground forces subsequently attack many of Earth's major cities, including Paris, London, Moscow, New York, Hong Kong, Rio de Janeiro, and Tokyo.

The battle in Los Angeles is the event depicted within the film, and showcases BLAA forces engaging armed forces of the United States of America; namely U.S. Marines, although National Guard, Air Force, and Army soldiers also see combat. The BLAA are seen giving the U.S. Marines a very difficult fight, utilizing their advanced weaponry to conquer most of Los Angeles. Furthermore, BLAA aircraft eventually arrive and appear to easily take control of the air above LA from the U.S. Air Force. Besides their ground and large air forces, the BLAA deploy a sort of command center which controls the unmanned flying drones. Within a day, the drones allow the BLAA to push most of the U.S. military force out of LA, killing thousands during the engagements. However, a squad of Marines is able to destroy the command center, disabling all of the drones and depriving the BLAA of their air assets. These Marines later retreat back to a command post, and join up with thousands of reinforcements ready to try and take back Los Angeles from the BLAA.

Home world
While nothing has been stated outright, it has been implied in interviews that the world of the BLAA is a chaotic, possibly war-torn place and that the BLAA involved in the invasion of Earth may not be part of the dominant force in their homeland.

Physiology
The BLAA are divided into four known warrior castes, but there are likely more non-combatant castes. Analysis of the warrior castes' biology indicates that they are highly developed, sporting redundant arteries and other blood vessels. Their heads are entirely sensory organs; their brains are located in a cavity behind their hearts, directly attached to the spine. The BLAA have large numbers of stem cells and platelets, enabling them to regenerate whole limbs that may be lost in combat, while their hardened exoskeleton allows them to take multiple 5.56mm shots before being too injured to continue fighting, like a human anti-projectile vest. However, if they are hit in the right place, they will drop dead. The primary human weapon used in the film, the M4A1 Carbine, uses the 5.56mm rounds and thus, the human military personnel who are fighting against the aliens have to shoot-to-kill (aim "to the right of where the heart would be.") This gives them a small but very real chance to fight back against the infantry of the BLAA.

All of the warrior-caste BLAA have substantial amounts of machinery implanted into their bodies, including communication, cooling, and weapons systems. Their perception is also very acute, supplementing their precognitive and retrocognitive abilities.

BLAA Infantry Caste
The BLAA Infantry Caste can be identified by their lack of grasping hands; instead, they have a weapon grafted onto each arm. Their average height is about 8'1". While they are taller than humans, they are proportionately thinner. As of the initial invasion, they are estimated to be the most abundant caste, numbering about 25 million in total. It appears that they are deployed in columns, led by a non-specialized officer.

Like the other castes, the heads of BLAA Infantry soldiers are nothing but sensory organs. All of their vital organs are concentrated behind layers of muscle and arteries in the right of their chests. A cooling system is also integrated into their body, with a heat-dispersing fan located in front of their organs. Unlike many of the other castes, they do not have as much machinery located on their back.

BLAA Officer Caste
The BLAA Officer Caste (referred to within the article as a "Specialized Officer") is the easiest caste to differentiate from the rest, identifiable by their slender build and four mechanical legs. They are also the tallest caste with an average height of 9'4". The Officers are specialized in commanding groups of infantry, augmented by an unusually large, well-developed brain and very keen eyesight which has been supplemented with additional electronics. They are most likely the least numerous caste, as they number roughly 2,000,000. BLAA Officers have been seen to lead fire-teams of up to four Operations Caste soldiers as well.

The Officer caste have the most substantial amount of cybernetic enhancements. As their legs have been wholly replaced, they are able to move at speeds of up to 40kph/24.8 mph with relative ease. Their legs are equipped with thrusters, similar to those on the drones, that allow them to hover rather than walk. Their right arm has an implanted weapons system that trades firepower for accuracy, while their left grasping hand has been replaced by a mechanical claw.

BLAA Operations Caste
The BLAA Operations Caste share many similarities with the General Infantry Caste, with a few notable exceptions. The BLAA Operations average about 6'11". The special forces appear to be a more intelligent Infantry soldier, expected to undertake specialized goals beyond that of simple shock troops. They also appear to be a middling caste, lacking the firepower of the Infantry and the intelligence of the Officer. While their strength is unknown, it is likely that they are between 2,000,000 and 8,000,000 in number.

Unlike the officer and infantry castes, the Operations have retained their left grasping hand and are able to make use of hand signals. Their weapons systems sport greater accuracy than those of the general infantry, but a less-powerful grenade launcher.

BLAA Intelligence Caste
The BLAA Intelligence Caste is likely specialized in their namesake, gathering information and laying down lines of communication. Averaging about 5'10", the Intelligence caste are the shortest and stockiest of all known warrior castes. It is unknown how many Intelligence Caste members there are.

Unlike all other warrior castes, the Intelligence Caste lacks any integrated weapons systems. However, they retain the large amount of cooling and communications machinery grafted to their backs. The lack of weaponry is made up for by their ability to utilize both grasping hands, which they use to operate machinery and vehicles, such as driving ground artillery platforms and operating walking guns.

Known Non-combat Castes
The known non-combat castes appear to be highly specialized and modified members of the BLAA. Their anatomy is radically different from that of the warrior castes.

BLAA Water Extractor
The BLAA Water Extractor is a specialized, partially biological pump that is used to move massive amounts of water quickly, growing as large as 100 feet in height. The Extractor's organs have been greatly reduced and compacted, leaving only organs that are vital to life functions. Extractors are highly intelligent and use an advanced form of communication to coordinate their actions for maximum efficiency.

The extractors are deployed along with the initial invasion force, landing off-shore and using modified tentacles to quickly pull water from the surrounding environment.

BLAA Medic
The film's creators have mentioned in interviews that there are "Medics" in the BLAA ground forces. It is not clear if the "Intel" caste actually performs this function due to the bio-mechanical nature of the aliens, or if this is referring to a similar caste which is more focused on medical support. There is a point in the film (during the fight on the freeway bridge) that standard warrior-caste aliens are seen dragging an incapacitated officer-caste alien back to safety, so it is established that they don't simply abandon their wounded.

Technology
Although the BLAA make use of orbital insertion to deploy soldiers into combat zones, the full extent of their space-faring capabilities is not known. Most BLAA weaponry use solid projectiles that appear to be propelled electromagnetically similar to a railgun, although their aircraft make use of a directed energy weapon.

Tactics
BLAA military doctrine seems to be concentrated on the principles of rapid dominance: using superior maneuverability and firepower to achieve a coordinated and devastating first-strike. This seems to come at the cost of armor protection, relatively speaking, for both infantry and vehicles. Observed BLAA vehicles tend to be very maneuverable, but to have exposed positions for their operators. Their battle doctrine seems to be based on the concept of eliminating enemy resistance before it can mount a coordinated retaliation.

Indeed, it seems that the concept of heavily armored units meant to survive protracted combat is an alien concept to the BLAA, as their forces seem relatively unprepared to fight human armored vehicles, and lose their combat edge when fighting human infantry in long battles of attrition. BLAA infantry weapons fire incendiary rounds, which are devastating against unprotected human infantry. However, surprisingly for the weapons of a technologically advanced alien race, human infantry body armor and flak jackets are able to provide reasonable protection against these incendiary rounds.

It seems that the BLAA have embraced coordinated combined-arms tactics to the point that each element of their military is only proficient at one specialized role: their infantry are proficient at fighting other infantry, and their vehicles are proficient at fighting other vehicles. Battle doctrine seems to be that when BLAA infantry encounter enemy vehicles, they are supposed to call in combined-arms support; sometimes from their light field artillery or hover-jeeps, but more often from unmanned-drone airstrikes. Conversely, their vehicle-based weapons - both field artillery and aerial drones - seem much more focused against other vehicles. While certainly an airstrike will damage human infantry, it is a disproportionate level of force which would have been better tasked against vehicles. The "walking-gun" field artillery, for example, fires a missile-volley which seems better suited for assaulting vehicles, as opposed to say, an up-scaled-version of their anti-personnel incendiary-round hand-held weapons. The result of this unit specialization is that they do not seem adept at asymmetric warfare tactics. BLAA infantry are repeatedly observed being over-matched by human military vehicles. An M1 Abrams tank was able to adequately pin down a squad of BLAA infantry on the freeway, until they had to call in light artillery support. BLAA infantry are also seen having a difficult time handling a small USMC squad driving LAV-25 APCs, which easily mowed past them. BLAA infantry are never seen using infantry-wielded anti-vehicle weapons, at best resorting to grenade-launchers, but these seem to be anti-infantry weapons and not very effective against vehicles.

Conversely, BLAA vehicles are frequently observed being successfully engaged by human soldiers wielding anti-armor weapons. Partially this is due to the fact that BLAA vehicles are based on maneuverability and not pilot safety, so they are easy to snipe, but even their unmanned drones seem to be unprepared to handle RPG attacks by infantry units. The group of marines that the film focuses on are able to overwhelm BLAA aerial drones and light vehicles after they acquire several shoulder-mounted M136 AT4 anti-tank rockets from the Forward Operating base. The BLAA's only counter to this is to try to deploy a greater concentration of drones, rather than switching to some kind of anti-personnel weapons.

The result is that if the BLAA are robbed of their air cover, due to their local command-and-control hub being destroyed, their infantry are particularly vulnerable to air-to-ground jet strikes and assault helicopters, as well as LAV-25 vehicles.

Infantry Weapons
All BLAA General Infantry soldiers use six-barreled machine guns with a mounted grenade launcher, although different Castes use different weapons systems. All BLAA General Infantry weapons use incendiary rounds with relatively low penetration, while their grenade launchers are capable of firing multiple rockets simultaneously.

Naval Mine
The BLAA naval mine is a high-explosive mine with an effective blast radius of 400 square feet. The mines are self-propelled and can be adjusted remotely to change both depth and position. They utilize high frequencies that make detection difficult.

Ammunition Sled
While not actually a weapon, the ammunition sled is a mobile container that is used to resupply ground forces in the field. Ammunition sleds can be dropped from ships, while their nine thrusters allow them to be easily "floated" from one location to another. They carry six fuel cells, weighing almost 150kg/330.75lbs each.

Multipurpose Weapon
The Multipurpose Weapon is the primary weapon of the BLAA Hovercraft. It consists of a double-barreled machine gun and a grenade/rocket launcher assembly mounted on a swivel. The launcher seems to use armor-piercing rockets that are ineffective against infantry, while the machine guns use standard incendiary ammunition. Two Multipurpose Weapons are mounted on each side of the Hovercraft and are operated by Intel Caste members.

Vehicles
Although the known BLAA vehicles make use of different forms of propulsion, none are wheeled. All of their vehicles are oriented toward greater mobility, at the cost of armor. In the case of all ground vehicles, this leaves the operators almost completely exposed to enemy fire.

Walking Gun
The BLAA Walking Gun is more of an infantry support weapon/field artillery than an actual vehicle. The Gun fires 16 small, guided missiles at a single target in order to destroy cover. While the gun is generally well-armored, a shot to one of the joints is able to temporarily stagger one, although the pulse jet engines at the rear of the machine are able to right it within a minute. Each walking gun is presumably operated by one of the Intel Caste members, as they are the only ones with two grasping hands. The guns are used to support both Operations and General Infantry during a battle.

Hovercraft
Although the hovercraft is armed with two Multipurpose Weapons capable of taking on squads of infantry, it does not appear to be a front line vehicle. Instead, it is relegated to supporting areas that are deemed safe. The Hovercraft uses adjustable thrusters mounted on four independently moving pads to compensate for terrain, giving it great amounts of mobility at the cost of large amounts of exposure and little armor.

Wedge Ship
The BLAA Wedge Ship is a type of drone aircraft, entirely reliant on a centralized command and control center to function.

The Wedge Ships are highly maneuverable, using pulse jet engines to make adjustments, as well as multiple exhaust engines. These exhaust engines vary in size and all of them are located at the back of the Wedge Ship. They are equally capable of reaching speeds of mach 7 or patrolling meters from the ground for enemies.

Eight wedge ships are able to go into a saucer formation for greater protection and better firepower. They are all capable of dismantling/disabling in a matter of seconds, as well as forming together in a matter of seconds. The wedge ships use ELINT (Electronic Intelligence) to detect enemy communications and home in on the source.

The Wedge Ship weaponry consists of a high-powered Directed-Energy Weapon. The DEW can be used to combine firepower with other wedge ships when they are formed into a saucer in order to maximize damage. At the back of the Wedge Ship are four extensions that are related to weapon-use. Wedge Ships also have a low-intensity spotlight mounted on the front of the craft.

Cargo Drone
BLAA Cargo Drones are used to drop supplies and reinforcements in BLAA-secured territory. While little is known of their capabilities, it is likely that they fill the same role as human cargo helicopters. Cargo Drones have been seen to deploy both BLAA fire-teams and individual Ammunition Sleds.

Central Hive
The BLAA Central Hive is a large structure that serves the field headquarters for a beachhead. The Hives are deployed with each landing force and are buried in the ground once BLAA soldiers have secured a sizable area.

The Hives are more like mobile structures than actual vehicles. While they do have a means of lift, their propulsion is only enough to get them airborne; they must be towed from one location to another by drones. If the hive is targeted, it can use its drones as ablative armor, sacrificing them to protect itself.

The Central Hive also serves as a small airfield, as its main role is to serve as the field headquarters for a beachhead and a coastal landing invasion. At the very top of the aircraft is where the communications relay is; their orders are relayed through these towers. The connection needs to stay intact in order for the drones to function.

Speculation

 * Given the decrepit appearance of their ships and equipment, it's possible that the BLAA are looking for a new home planet, possibly due to their old home being uninhabitable because of warfare or some other cataclysm. This would explain their War of the Worlds-esque landing method, as well as their relatively low level of technological advancement for a space-faring civilization.
 * Based on the documents found on the Unidentified Enemy website, it's possible that the BLAA may actually be a scavenger species that integrates machinery originally created by another, more advanced native species.
 * It is also hinted that the BLAA homeworld was lost in an apocalyptic world war. So the BLAA seen in the movie could be survivors of one of the sides that fought in this war and that their current generation is a spaceship-born generation. That would explain the relatively old and worn appearance of their equipment and vehicles for a capable space-faring civilization.