Metal Gears are massive war machines from the Metal Gear series. While first introduced in the original Metal Gear, their origin begins in Metal Gear Solid 3, which took place during the height of the Cold War. The original Metal Gear design and theory was created by Aleksandr Leonovitch Granin, who believed in combining artillery and infantry into one unit, capitalizing on the mobility of infantry combined with the firepower of artillery. He saw the only solution for this being an armored tank with legs. He was very opposed to the Shagohod for this very reason, as it was limited by its screw propulsion system.
Notable Metal Gears
Metal Gear RAXA
By the chronology of the Metal Gear franchise, this is the first Metal Gear created. It was seen in Metal Gear Solid: Portable Ops. It was built by Nikolai Stepanovich Sokolov, based on Granin's original plans. It acted as a mobile nuclear launch platform for nuclear missiles called MIRVs. It was relatively slow and walked using its four legs. To compensate for its speed, it could be attached to a rocket and fired near the intended target. It would then detach from the rocket and parachute to the ground, at which point it would fire its missiles.
Metal Gear ZEKE
Appears in Peace Walker for the PSP and in the HD Collections for the XBOX 360 and PS3. After Snake rescued Huey from Hot Coldman, Huey went to work at Mother Base, helping the MSF destroy his own creations on the Peace Walker project. To achieve this end, he designed and helped to build a new Metal Gear nicknamed ZEKE. Later on in the story, Dr. Strangelove came onboard to help craft its AI. When the ZEKE was finished being built, Kaz told Snake that he loaded up Coldman's unused nuclear missiles onto ZEKE because that way MSF would have its own deterrent against any world power planning to destroy them, as well as keep them out of the hands of terrorists or others who could use them for evil. By doing this, MSF essentially became a nation unto itself.
However, shortly after the Peace Walker incident, the Patriots' own Agent Pacifica managed to hijack the finished Metal Gear ZEKE and tried to use it as leverage to force Snake to rejoin the Patriots. When he refused, Pacifica armed a nuclear missile and prepared to launch it at the East Coast of the US to paint the MSF as pariahs and see the Mother Base nuked into oblivion in a retaliatory strike. Snake and the MSF were then forced to destroy ZEKE, sending it to the bottom of the ocean along with Pacifica. However, it is unknown whether or not Pacifica died with it or escaped from the cockpit with scuba gear.
In this game, the player can build a fully-functioning ZEKE by collecting scrapped parts of other robots that Snake and the MSF fight in the game, including different versions of the Pupa, Chrysalis, Cocoon and even Peace Walker itself. It is armed with standard missiles and chainguns, but some optional parts can be salvaged to make it even stronger, like a railgun to increase its attack power, extra armor, a radar dish or booster jets. Also, by infiltrating the AI Pod of any robots that have been damaged, the player can retrieve AI boards to increase ZEKE's effectiveness in the field. ZEKE can be sent on Outer Ops missions, providing a big advantage against enemy forces.
Metal Gear TX-55
Metal Gear TX-55 appeared in Metal Gear for the NES and MSX. Metal Gear TX-55 was created by Dr. Pettrovich. It functions as a mobile nuclear platform. In the NES version of Metal Gear, the player never confronts the Metal Gear itself, instead fighting the supercomputer that controls it. The TX-55 was armed with a laser cannon along with a 20mm vulcan gun and multiple medium-range warheads. However, none of its arsenal was put to use, as the TX-55 was destroyed by Solid Snake before completion.
Metal Gear D
Metal Gear D appeared in Metal Gear 2: Solid Snake on the MSX. Metal Gear D was a redesigned version of the TX-55 Metal Gear model, featuring a more streamlined design. Metal Gear D's arsenal was comprised of a 5.56mm machine gun, 60mm Vulcan Gun, and a missile pod with a capacity of six warheads. It was developed by Drago Pettrovich Madnar for Zanzibar Land, much like TX-55 was for Outer Heaven. However, unlike the TX-55, he designed D out of his own free will. Metal Gear D was piloted by Gray Fox during Zanzibar Land's raid of nuclear disposal sites. Solid Snake learned that Metal Gear D's legs were vulnerable to attack from hand grenades, and he exploited this knowledge while battling Gray Fox, in command of the Metal Gear.
Metal Gear REX
REX was the Metal Gear from Metal Gear Solid. It was designed by Dr. Hal "Otacon" Emmerich, and built in Shadow Moses. Its weapons include vulcan cannons, anti-tank missiles, and a free-electron laser. It is capable of launching a nuclear missile through the use of its high powered railgun. This allows REX to attack its enemies yet remain untraceable, since the missile doesn't need to any propellant for launch. It is far more armored than its predecessors, covered in thick compound armor. This also proves to be one of REX's weaknesses, as the pilot has no way to see out of the cockpit, and must rely on its radome for all external readings. The radome itself is weak, and a direct attack against it will blind the pilot, forcing him to open up the cockpit to see. Otacon explains that he built this weakness in on purpose.
Metal Gear RAY
Metal Gear RAY premiered in Metal Gear Solid 2: Sons of Liberty. It was developed by the U.S. Navy, based on the leaked plans of Metal Gear REX. It differs from the other Metal Gears in that it was not built as a mobile launch platform, but rather as a Metal Gear killer, designed to fight and destroy any and all REXs it encountered. They believed that this new type of Metal Gear would render all other Metal Gears useless and inferior to RAY's maneuverability and newly acquired firepower.
Its weapons include two machine guns and six missile tubes, though its main weapon is a water jet cutter, which fires a concentrated stream of water with such force that it's capable of cutting through REX's thick armor. RAY was designed to be far more mobile than previous Metal Gears, and emulates many systems of organic life in its design. It uses synthetic muscle tissue that contracts when an electric current is applied to give it its high maneuverability. Its circulatory system pumps a nano-paste across its body that flows into and repairs breaks in RAY's armor. It even has a nervous system composed of conductive nanotubes that can bypass damaged connections to continue its full operations. All these features join together to make it functional on land and sea. Metal Gear RAY's armor is composed of Ceramic-Titanium Alloy.
Arsenal Gear first appeared in Metal Gear Solid 2: Sons of Liberty.
Arsenal Gear was a submersible, mobile fortress with the ability to monitor, block, and tamper with internet communications in order to further the goals of The Patriots. After the tanker incident , The Patriots sent out a dummy tanker, sank it, and used it as a means to cover up the construction of Arsenal Gear. Arsenal Gear was the largest Metal Gear ever constructed requiring a huge crew to operate and defend it. The massive vehicle needed to carry 25 mass-produced Metal Gear RAY's to help defend itself. Arsenal Gear was ultimately a flawed creation, as pointed out by Solidus Snake; it was virtually worthless without a nuclear payload, the RAYs to protect it, and full sea, land, and air support. Unless it was capable of sustaining such needs, Arsenal Gear was nothing more than "a gigantic coffin."
Gekko is the new mecha featured in Metal Gear Solid 4: Guns of the Patriots. The Gekko is a mass-produced unmanned bipedal unit manufactured by ArmsTech Corp, and designated "Irving" by the U.S. Military; this stems from the American codename for the Nakajima J1N "Gekko" twin engine night fighter aircraft from WWII. Their frequent use by PMCs has caused it to be a replacement for tanks as a means of conducting armored warfare in Urban areas. The Gekko is used particularly by the Praying Mantis company, although the Gekko have widespread use within the PMC community.
Although not a literal Metal Gear, the top half of this mecha is reminiscent of the Metal Gear REX design while the organic legs are somewhat similar to that of Metal Gear RAY. It is unmanned and uses two large cameras as its "eyes", one mounted on its head, the other at the front of its hip assembly. These are backed up by other sensors, mostly passive. New features include a small robotic tentacle used to pick up small objects or grab targets. The Gekko is incredibly agile and maneuverable, thanks to a pair of flexible limbs that can act as either legs or arms. The legs are made from artificial muscle tissue cloned from embryonic stem cells of ungulate embryos. With these legs, the Gekko can pick up a man and throw him hard enough to penetrate a brick wall, deliver a kick that can overturn a 6x6 truck, dodge an RPG and kill its shooter, climb walls, crouch to enter buildings, run at speeds equivalent to a motor vehicle, and leap huge distances through the air. This model comes in multiple variants. Two of these variants are designed for standard combat; both carrying anti-personnel machine guns mounted inside the "nose", while one carries heavier machine guns and missile launchers. A third variant is the special purpose "Suicide Gekko", designed to invade enemy facilities in groups before self-destructing en masse.
Similar in combat terms when compared with traditional Metal Gear models, relatively little firepower is needed to actually destroy one. A quick blast with an assault rifle may cause one to trip if shot in the legs. Corresponding shots to the "neck" can destroy a Gekko with small arms such as a M4 Carbine or FN P90 . However when a Gekko falls it can quickly regain its footing even if tripped onto its head. The Gekko makes use of sound in psychological warfare, particularly animal noises (such as cicadas while on the prowl to create an atmosphere of unease, and bull sounds in direct combat as a means of unnerving the enemy). They feature characteristics that are biomechanoid to some degree, as they have been shown to "bleed" when sliced at the legs (understandably as the machine could use a blood-like self-repairing nanopaste like the RAY), though severe wounds on seemingly mechanical components have been known to "bleed" as well. In addition, they expel a green liquid while roaring in certain situations.
In a pre-release interview, Metal Gear director Hideo Kojima stated that the Gekkos are not the game's titular Metal Gears, stating that they are more like a jeep or a Tank compared to the conventional Metal Gears such as REX and RAY.
Metal Gear Mk. II/III
A robotic companion to Snake called Metal Gear Mk. II appears in Metal Gear Solid 4. This Metal Gear Mk. II is similar (albeit a bit more angular in appearance) to the Snatcher version and is controlled by Otacon, who uses it to deliver ammunition and advice to Solid Snake. The Metal Gear Mk. II can also be used as a recon device, turn invisible, and shock enemies knocking them unconscious. However, it also runs on batteries which run out of juice due to consumption while in operation. The Metal Gear Mk. II is automated in the game, but can be controlled by the player if needed. After the Eastern Europe mission, the Metal Gear Mk.II is destroyed by Vamp, and replaced by the similar Metal Gear Mk.III, which accompanies Snake at Shadow Moses and Outer Haven. The Mk. III has the same body as the Mk. II, but with a red-colored exterior, and serves the same function.