Gekko

The Gekko is a large unmanned autonomous fighting vehicle developed by AT Corp for use in ground combat. Officially designated IRVING by the United States Army, Gekko are colloquially called "lizards" after the species of small lizard with a similarly spelled name: gecko. These war machines were created using a combination of technologies used in the production of Metal Gears REX and RAY. However, Gekko are not Metal Gear. Unlike true Metal Gear, Gekko have no nuclear launch capability. Instead, they are more akin to infantry fighting vehicles, with multiple units acting as a coordinated team in support of ground forces.

Physical characteristics
A Gekko has a large mechanical turret-like head whose shape gives the impression of a distinct face and snout. This is connected via a neck to a smaller body at the back of which are two large, hip-like structures. Like the head, the neck, body and hips are mechanical. All are connected via mechanical movable joints. The joint connecting the head to the neck allows the head to turn 360 degrees.

Attached to the hips are a pair of very strong legs with three-toed clawed feet and a single large claw on each heel. These legs, unlike the head, neck, body and hips, are biological, save for the claw on the heel. The legs are composed of artificially created muscle tissue cloned from the stem cells of ungulate embryos. Gekko walk on their toes. Because each hip is connected to the body via a ball joint, a Gekko's legs have a very large range of motion. For unknown reasons, the central front area of the hips have a warning sign forbidding anyone from trying to strike at this area.

The engine system of the Gekko has a power output of 650HP.

Atop the head and between the hips at the front of the body is a dome-shaped sensor capable of detecting visible light and infra-red, and equipped with night vision and other enhanced imaging abilities, such as the ability to scan through solid objects. A Gekko also has aural sensors, enabling it to detect sound.

Being bio-mechanical, a Gekko has a circulatory system that uses blood to nourish its legs. If cut or shot, its legs bleed. Since they are made of living muscle tissue, the legs produce lactic acid which builds up with muscle activity. This acid must be periodically expelled. Gekko do this via a release of accumulated lactic acid as a yellow-green liquid from an orifice between the hips.

Gekko communicate by lowing like cattle or chirping like cicadas. If shot in the head with sufficiently high caliber ammunition, they squeal on the bullet's impact. Should they fall over on their backs due to damaged or otherwise incapacitated legs, they screech like wounded, frightened animals. Catastrophic damage elicits a loud groan before the unit collapses and explodes.

They also act as carriers for Dwarf Gekko, which are a smaller, spherical, three-armed variant of the Gekko designed specifically to accomplish combat and infiltration situations that regular Gekko cannot due to their size.

As of 2018 the latest model is the 'Block 30' unit. Its Artificial muscle contraction rate is increased by 6% and the chassis is made from honeycomb boron-fiber reinforced plastic. It is equiped with a milliwave radar, low-light camera, infrared camera, acousting positioning gear, chemical sniffer and its armed with a .50 calibre machine gun. The Block 30 is utilized by Desperado enforcement.

Abilities
Because of the strength of the legs and feet and the sturdiness of the unit, Gekko are able to run at high speed and leap great distances into the air, enough to clear low-story buildings. They can use their legs as formidable weapons. A Gekko's kick is powerful enough to completely overturn a vehicle as big as a 6x6 transport truck with minimal effort, and can strike a human opponent with such force that his body hits a wall hard enough to shatter it on impact. The claws on their feet and heels, and the range of motion provided by their hip joints, allow them to move with remarkable agility for such large entities; a Gekko was observed dodging a rocket-propelled grenade round fired at it while executing a lethal counter-attack against the shooter. Gekko can climb up into areas it would seem impossible for them to reach. They are able to scrunch down into a surprisingly compact size and enter low-ceilinged areas it would not seem possible for them to enter, provided the area is wide enough for them to fit. A Gekko, for example, was able to drop down through a ceiling into a corridor in the nuclear disposal facility on Shadow Moses Island scrunched down, surprising Solid Snake as he was about to enter the corridor round a corner. It patrolled the corridor back and forth in this position. Despite these abilities as well as the relative versatility of the mechs compared to other armored mechs, even these abilities have their limits: Although they technically can operate within indoor areas, it was demonstrated to be somewhat of a hinderance, and they cannot operate in tight spaces such as ventilation shafts. Because of this limitations as well as the Gekko's continuous deployment into urban counterterrorism operations in the height of the war economy (where such places were vital to completing these ops), this led to the development and field-testing of a minature version of the Gekko, called the Dwarf Gekko.

A Gekko possesses a long retractable whip-like appendage that it can use to pick up, examine and manipulate small objects, or to throw small explosives such as grenades. The appendages can also be used to restrain enemies, which included impaling them in the body, as evidenced by what they did with Raiden in South America.

A Gekko's head, body and hips are extremely well armored. No ammunition can penetrate it save very high caliber ammunition such as .50 BMG. It can withstand the impact of rocket-propelled grenades; these only serve to turn its attention on the attacker. Some Gekko also possess anti-missile counter-measures that cause any incoming missile launched at it to veer harmlessly up and away as it nears the unit.

Its legs are not armored, but are tough enough to withstand sustained bursts of machine gun fire before giving out. if only one leg is so injured, the Gekko will drop to one knee but will defend itself by shooting at the attacker with its onboard machine gun. If both legs are so injured, the unit falls over on its back, helpless. But this is only temporary; the damage soon heals and the unit gets back up on its feet. Because of the legs' semi-organic nature, they are also susceptible to tranquilizers. However, they only cause the foot to fall asleep. The head and hips are still active to some extent.

Gekko are completely autonomous and unmanned. A Gekko has an AI that allows it to differentiate enemies from allies and civilians, and, coupled with its speed, agility and ability to compact itself, to tenaciously chase an enemy through multiple levels of a structure and investigate signs of the presence of a hidden enemy, including picking up and examining objects that indicate such a presence, such as a fallen lit cigarette. This AI is somewhat limited in its intelligence, though. A Gekko, for example, can use its enhanced visual sensors to image the contents of a box, but its AI is not smart enough to determine whether or not the contents are in the shape of a human body or not. However, Gekko can, at times, display surprising canniness. On Shadow Moses, for example, a Gekko was able to use an elevator to get up to the first floor of the nuclear warhead storage building from the lower levels. Its AI is also not immune to dizziness, which it can experience if its dome sight is spun around by an enemy. This was best demonstrated during Raiden's fight with the Gekko in South America, where Raiden at one point spun the dome sight of one of the Gekko, causing the Gekko to walk precariously away before stumbling and falling over.

A Gekko will not harm civilians. Should a target be in a group of civilians, a Gekko will not take any action. During the rescue of Dr. Naomi Hunter, for example, Solid Snake was able to run past a Gekko in a market in South America with the unit's sensors fully trained on him, by running in a group of fleeing civilians. The unit did not attack though he passed directly in front of it a few feet away, since civilians would have been harmed.

A Gekko has the ability to go into a low-powered state in which it is scrunched down in a compact size, does not move and appears to be deactivated. This appearance is false. Its passive sensors remain active. Should any object beyond a certain size approach within their range, or should any loud noise occur, the unit will awaken and rise. On Shadow Moses, for example, two Gekko were in this state on each side of a small canyon. Rats and other small creatures were able to move around near them without waking them. But if Solid Snake or his Metal Gear Mark III approached one it awoke. If he destroyed one with a very high caliber weapon, the other was immediately awakened by the explosion.

Gekko are, however, exceptionally vulnerable to electric currents. This was best demonstrated at Shadow Moses Island, where a Gekko ended up stepping on a reactivated electrified floor, and ended up paralyzed and screaming before collapsing and then exploding.

When not in use, Gekko can be transported in an inactive state on a transport truck. Their compactness in this state allows them to be easily loaded and unloaded.

Weaponry
The Gekko's deadliest weapons are its powerful legs. A Gekko can easily kick over a large, heavy vehicle such as a deuce-and-a-half. During a conflict in a Middle Eastern City, one was seen to kick over a large transport truck onto a group of insurgents who had taken cover behind it, crushing them. Gekko are known to execute a devastating sweeping roundhouse kick against enemies within range of their legs. This kick almost invariably ends the life of any enemy it strikes. Gekko also are able to kill with their legs by jumping and landing on enemies, stamping on them, grabbing them with their toes and slamming them into the ground with lethal force, and kicking them in the manner that a soccer player kicks a football. Additionally, a Gekko can scrunch down with its head lowered, direct the top of it at an enemy and run at the enemy like a bull, killing him, or in the case of the enemy being a cyborg, seriously injuring him with the impact.



Apart from its legs, Gekko are capable of carrying a number of onboard weapons. With regard to such weapons, Gekko are highly modular. All Gekko carry an internally mounted machine gun near the snout. Gekko are also known to carry a pair of M2 Browning .50 caliber heavy machine guns, tube launchers for anti-tank missiles, or an array of grenade launchers on the back of the head.

Gekko also carry grenades which they lob into out-of-reach areas with their retractable manipulators to kill or flush out enemies.

Besides possessing the above-listed offensive measures, Gekko also are equipped with defensive systems. The most notable of these is its anti-missile counter-measures that defect missiles away from it.

A variant known as the "Suicide Gekko" carry a nuclear demolition charge in their heads. These Gekko possess no onboard weapons apart from the standard internal mounted machine gun. Their function is to get close to a target and detonate their charges, destroying themselves and the target. However their effectiveness can be limited, as they can be destroyed by very high caliber weapon fire before they get within effective lethal blast range. Even if they get within range, their bombs emit an audible countdown as they arm, during which time they are completely immobile and thus fully vulnerable to attack. However, enough of them converging on a target at once can still ensure the target's destruction, since there has to be enough defenders to destroy them all before they arm and detonate. Otherwise enough can still successfully arm and detonate while others are destroyed before they can do so.

History
In 2014, Gekko were used extensively by the PMC forces under Liquid Ocelot.

Several Gekko were deployed in the Middle East to eliminate a local militia. During the encounter, two Gekko encountered Old Snake, who managed to elude them with his OctoCamo.

Many Gekko were deployed in South America and killed several of the local rebels, and tried to eliminate Snake in order to recapture Naomi. During their search, they also attacked a marketplace. The Gekko then encountered and attacked Raiden (the third Cyborg Ninja), who countered by slicing and destroying several units.

At least two Gekko were deployed in Eastern Europe to eliminate Snake along with Big Mama and the Paradise Lost Army.

Several of the Gekko units were also deployed to Shadow Moses Island in order to prevent Snake from reaching Metal Gear REX. In addition, Suicide Gekko were deployed to blow up the supply route building on Shadow Moses Island, after Liquid Ocelot retrieved REX's rail gun. They arrived just after Old Snake defeated Vamp, and just as several units were about to self-destruct, Raiden arrived and saved Snake. While Raiden and Vamp engaged in knife compact for their final showdown on top of REX, Snake used his rail gun to destroy the Suicide Gekko that were either attacking or arming themselves for self-destruction. After Raiden's victory over Vamp, Otacon (via the Metal Gear Mk. III) used the reactivated REX's missiles the destroy the oncoming Suicide Gekko. After Naomi's death, Snake (with Otacon's directional advice) used REX to escape the facility while Raiden cut a path for Snake and REX. While Snake and REX were able to get away, the combinated blasts from the Suicide Gekkos caused the building to fall on Raiden.

Finally, several Gekko units were deployed within Outer Haven but were later deactivated when Snake and Otacon uploaded FOXALIVE, destroying the repaired GW AI, the SOP System, and the other AIs (TJ, TR, AL, and the master AI, JD).

Despite the destruction of the Sons of the Patriots system via FOXALIVE, Gekko were still mass-produced, being completely unmanned. Several Gekko, named Gekko UG (standing for Unmanned Gear), were later utilized by Desperado Enforcement LLC as well as their ally, World Marshal Inc. in the events of 2018, also containing MCFC electrolyte cores. They were somewhat obsolete. During a training session, Raiden, after accessing a Desperado-related computer terminal via an access pass, inadvertently lured a Gekko UG over to his area, forcing him to take it out alongside enemy reinforcements. During this time, it also came in three different camo colors: One was primarily a green camo pattern; another was an urban-style camo pattern; and the last was colored in black and red patterns derived from Desperado.

Game design
The term "Gekkō" comes from 月光, the Japanese word meaning "moonlight," while the U.S. codename "IRVING" stems from the American codename for the Nakajima J1N "Gekko" twin-engine night fighter aircraft from WWII. During an interview, Hideo Kojima stated that the Gekko were not the titular Metal Gear of Metal Gear Solid 4: Guns of the Patriots, stating that they are more like a jeep or a tank compared to the actual Metal Gear.

The weapons mounting of a Gekko is similar, but not identical to, the M151 Remote Weapon Station used by real life armored vehicles. It is unclear how a Gekko's heavy weapons are restocked, since it has no obvious capacity for reloading its own weapons in the field; presumably they must withdraw once the fixed armament is depleted, though in the context of the game they have infinite ammunition. Though they are capable of carrying Dwarf Gekko on the sides of their heads, as seen in the game's cutscenes, this configuration is never encountered during actual gameplay.

Some of the models have various letters and numbers on them, hinting that the various Gekko were placed into various divisions within Outer Heaven. in addition the color scheme of a gekko differs depending on which PMC is encountered. However, with the exception of Metal Gear Rising: Revengeance, these changes are mostly unnoticeable.

Trailer appearances
In a pre-release trailer for Metal Gear Solid 4, some Gekko managed to wipe out the Middle Eastern Militia unit in Ground Zero. Afterwards, they also released a greenish-yellow fluid (later confirmed to be lactic acid). In addition, within the Red Zone, they also were marching with a platoon of Strykers belonging to Praying Mantis, resulting in Snake (who was spying on them for reconnaissance) almost being spotted by one. Although most of these weren't shown in the game itself, the former was nonetheless implied to have happened off-screen with Snake being pursued by Gekko early in Act 1.

Gekko are also seen in the trailer for Metal Gear Rising, although it is currently unknown how they are still functioning during the time period (taking place after Metal Gear Solid 4, when the Patriots' AIs were deactivated via FOXALIVE).

Super Smash Bros. Brawl


The Gekko is one of the three mecha, along with Metal Gear REX and Metal Gear RAY to appear in the Shadow Moses Island Stage in Super Smash Bros. Brawl. Also, due to the fact that Metal Gear Solid 4 was released after Super Smash Bros. Brawl, this technically marks the Gekko's debut game.

Completing All-Star Mode with ten characters will unlock a Gekko trophy with the following description:

"A Metal Gear with a pair of animal-like legs. Gekko are mass-produced weapons used in military combat. Its distinctive legs allow Gekko to move at high speed, jump incredible distances, and even cling to walls, giving it unprecedented mobility. Other noteworthy features of this model include prehensile tentacles strong enough to pick up soldiers and its signature deafening roar."

Note that it incorrectly labels it as a "Metal Gear" and there is no "roar" (unless you count the mooing).

Metal Gear Solid 4
Heavily armored and highly agile, Gekko are difficult to deal with unless armed with a sufficiently powerful weapon, such as the M82A2 .50 caliber BMG anti-material sniper rifle or the rail gun. Their roundhouse kick causes significant damage even at the game's lowest difficulty; at higher difficulties it is almost certain to cause death. They lob hand grenades if Snake retreats into an out of reach area, fire at him with their onboard weapons and run at him with their bull-like charge. Missiles from portable missile launchers are usually deflected by a Gekko's anti-missile counter-measures.



However, they do have known weaknesses. The first is their legs. Though very strong, they are biological and therefore are vulnerable to gunfire, albeit only prolonged bursts, and are also vulnerable to tranquilizer darts from the MK 22 or Mosin Nagant. Enough bullets in one leg will only bring a Gekko down to one knee; it will defend itself using its onboard weapons. Both legs must be shot with sustained gunfire to make a Gekko fall helpless on its back. Tranquilizer darts to the legs will also bring a Gekko to this state. However, this does not last long. The effect soon wears off or the injury from the bullets soon heals, and the unit rises to its feet.

A second weakness is the sensor dome on the head. If this is destroyed, the Gekko explodes. It is less armored than the rest of the head and is therefore vulnerable to gunfire, though it requires a very long, sustained burst to penetrate the armor. Normally it is very difficult to target this sensor given the length of time needed to penetrate the dome's armor, and Snake has to stand still long enough to aim and fire at it, leaving him open to counter-attack. However, if the Gekko were first brought down helpless on its back, then Snake could safely stand still, target the dome and shoot it long enough to destroy it, though the player must take care to stand out of range of the ensuing explosion.

A third weakness is the fact that a Gekko's armor can be easily penetrated by ammunition of large enough caliber, such as from the aforementioned M82A2 sniper rifle or rail gun. One fully charged shot from the rail gun to any part of a Gekko's head will destroy the unit. The player will hear the unit's loud groan due to catastrophic damage, after which it collapses and explodes. A maximum of two shots from the M82A2 to the head will have the same effect. The first shot makes the Gekko wobble and squeal. If it is firing at Snake when the shot hits, its shooting stops. The second shot elicits the same reaction before the groan, collapse and explosion. If first shot is well placed, the second one becomes unneeded.

When fighting the Suicide Gekko in REX's hangar during the Twin Suns act, it is recommended that the M82A2 be used instead of the rail gun, as the M82A2, as, unlike the rail gun, it does not need to be charged for a "killing" shot, eliminating the time Snake is defenseless, during which the Gekko can approach and converge.

The Suicide Gekko's warning voice that verbalizes the self-destruct countdown were recorded by Kris Zimmerman, who served as the English voice director for Metal Gear Solid 4.

Metal Gear Rising: Revengeance
The Gekko made a reappearance in Metal Gear Rising. Their attack patterns are largely the same as in Metal Gear Solid 4, although they don't do as much damage in this game as before.

Other appearances
The Gekko appeared in metalgearsolid.com's Versus Battle page, where they fought against Metal Gear ZEKE.

WEAKNESSES: 360-Degree Optics + Spin = Dizzy FEATURED FACT: Created using a combination of technologies from METAL GEAR REX & METAL GEAR RAY FEATURED GAME: METAL GEAR RISING: REVENGEANCE''"
 * "''STRENGTHS: Agility, Titanic Legs, Weapon Packs
 * - Gekko Herd description on Versus Battle

Appearances

 * Metal Gear Solid 4: Guns of the Patriots
 * Super Smash Bros. Brawl
 * Metal Gear Rising: Revengeance
 * Metal Gear Solid: Peace Walker (easter egg only)