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This article is about Peace Walker, the bipedal nuclear weapon. You may be looking for the game in which it was featured.

Peace Walker, also known as Basilisk, was a walking nuclear-armed AI weapon developed by Huey Emmerich and Strangelove.


Although capable of bipedal locomotion, Peace Walker's primary mode of transportation was quadrupedal. It utilized stealth from radar and satellite images, which drastically reduced any chance of it being destroyed in a nuclear attack. Its most devastating weapon, however, was a massive hydrogen bomb mounted to the frame that was more powerful than even the Tsar Bomba, so that if necessary, it could sneak into enemy territory and self-destruct. It carrying this hydrogen bomb was also one of the primary reasons why bipedalism/quadrupedalism was required for its development, as it couldn't be loaded on missiles nor could it be carried by a strategic bomber due to its immense size. Its overall capabilities relating to nuclear deterrence was referred to as a land based version of a SSBN. Its footprint size alone was also large enough to dwarf even an elephant, one of the largest animals currently alive.[7]

Peace Walker was controlled by two AIs: the Reptile Pod and the Mammal Pod, which were modeled after the human cerebellum and cerebrum, respectively. While the Reptile Pod was mainly responsible for operating the main frame, the Mammal Pod possessed more advanced decision-making capabilities, giving it the capacity to launch a retaliatory nuclear strike at the most effective target. The Mammal Pod AI's neural processes were modeled after the legendary soldier The Boss.

Unlike Metal Gear, Peace Walker was completely incapable of launching a nuclear weapon by itself, only launching out of self-defense, as part of the theory of deterrence. However, it could be tricked into launching a nuclear weapon into a country if supplied with false data, which could depict an imaginary Soviet nuclear attack on the U.S. It could also transmit this false data to third parties, such as NORAD. This was the result of it possessing covert channels to NORAD's early warning system made of DSP satellite-mounted infrared sensors and an array of surveillance radar stations across America, meant for human decision making, due to Peace Walker being required to act autonomously. These channels were also used for the testing bed. Combined with the fact that the data would be transmitted via a spread spectrum multi-length frequency pattern, rendering even electromagnetic pulses ineffective in blocking the signal, this was arguably its most dangerous ability outside of its hydrogen bomb. The method of inputting false data is via a nearby radio-satellite van.[8] Aside from the nuclear launcher, Peace Walker included a radiation generator, a pair of flamethrowers, regular missiles, s-mines and mole missiles. All of this weaponry possessed a heavy emphasis towards defense. Also, if someone tried to attack Peace Walker, it would abort its previous command and go into a small threat suppression mode.

Peace Walker was the only AI weapon capable of self-generated speech.


Peace Walker's former codename of "Basilisk," as well as the Sandinistas nickname for the weapon "Basilisco," is a reference to the lizard of the same name, which is able to travel atop any terrain, stand on two legs, and even run across water, similar to Peace Walker's all-terrain capabilities. The name was also a reference to the mythological basilisk, a highly venomous creature that is considered to be the "King of Snakes." A Roman legend told of a knight who once killed a Basilisk with a spear, though he and his horse ended up dying after the venom seeped up the spear. Peace Walker also possessed the ability to petrify enemies (albeit, via an immobilization ray).

The Reptile Pod's designation was AL-Aurelia 8000; the initials are based on those of Abraham Lincoln, while Aurelia is a synonym for "chrysalis." The Mammal Pod's designation was BS-Imago; the initials are based on an abbreviation of "Boss," while Imago is the name given to an insect's final life stage.

Peace Walker's head featured the emblem of a butterfly. This was in reference to the fact that Peace Walker was the completed form of the AI (i.e., it could process and decide on how to handle nuclear retaliation). The machine itself was referred to as such by Big Boss, during a conversation with Huey Emmerich.[9]



In 1973, CIA Station Chief Hot Coldman commissioned the creation of Peace Walker (originally designated "Basilisk," and known to the Central American locals as "el basilisco") in order to fulfill his vision of the "perfect deterrent." He recruited Huey Emmerich to create the frame for Peace Walker and Strangelove to create the Mammal Pod AI. Between 1973 and 1974, frequent tests in regards to its maneuverability were carried out in Costa Rica. One of these tests, at El Cadalso, was witnessed by Chico, a Sandinista child soldier.

Peace Walker Incident[]

Main article: Peace Walker Incident
Peace Walker

Peace Walker in quadrupedal form.

Though the weapons systems and the frame itself were eventually completed, the Mammal Pod was still undergoing construction by November, 1974, since the AI required another component that would ensure Peace Walker's role as the "perfect deterrent." Huey later refused to participate further in the weapon's development, after discovering Coldman's intentions to have it launch an actual nuclear warhead to test its effectiveness, gaining an advantage in future negotiations with his superiors.[10] After proving to the CIA that Peace Walker's AI could launch a nuclear strike unaided, Coldman hoped to manufacture more units with their funding. Deployed along the entire Caribbean coast of Central America, the Peace Walker system would place within its range all of North America, South America and the West Indies, making Latin America the cockpit of a "New Cold War."

Coldman's Peace Sentinel later captured Militaires Sans Frontières commander, Big Boss (Naked Snake), when the latter attempted to destroy the AI, while he was distracted by the AI's imitation of The Boss. Strangelove eventually deduced the missing data required for the AI to function effectively by torturing Big Boss, after which Coldman revealed the first target for Peace Walker's nuclear launch: the MSF's Mother Base. Part of the reason dealt with eliminating the MSF, although he also intended that the trade winds in that location would scatter the fallout throughout Central America, poisoning crops and fish markets, thus allowing for "free hands" to help with the mass production of Peace Walker.

Big Boss later battled the bipedal form of Peace Walker, causing some damage to the weapon, though not enough to completely incapacitate it. It began malfunctioning as a result of the damage, until Coldman's Hind D attacked the AI pod with machine gun fire, provoking Peace Walker to cease targeting Snake. It then transformed into its quadrupedal form and followed Coldman's Hind towards the Nicaraguan-Costa Rican border, while Big Boss, astride The Boss's horse, gave pursuit. Peace Walker was able to make it to a United States missile base in Nicaragua, where it would launch its nuclear strike through false data, after Strangelove input the coordinates.

However, KGB spy Vladimir Zadornov betrayed Coldman, with whom he had previously allied, and changed Peace Walker's target to Cuba, hoping to cause anti-American sentiment to spread internationally, thus giving the Soviets an upper hand in the Cold War. Coldman was then shot by Zadornov, though he missed the killing shot deliberately because he still needed the launch code. After Zadornov was stopped by Amanda Valenciano Libre's Sandinistas, and arrested by the Militaires Sans Frontières, Coldman, dying from blood loss inflicted by Zadornov's earlier gunshot, activated Peace Walker, causing the weapon to commence launch preparations for a "retaliatory" nuclear strike towards Cuba. Using the launch verification code "1976," Peace Walker also began transmitting false data towards various third party organizations, such as NORAD and the Pentagon, nearly causing an all out nuclear war. As Coldman died before he could give the abort code (knowing full well that he would die soon after launching it), Big Boss and Strangelove were forced to destroy Peace Walker.

Although Big Boss managed to destroy Peace Walker, rendering it unable to launch a nuclear strike, it was still transmitting false data towards NORAD and the Pentagon, causing a nuclear war to become inevitable. Even Big Boss removing the memory boards from the Mammal Pod's AI (which had allowed him to get inside) was not enough to end it, as authority for transmitting the false data was passed on to the Reptile Pod. However, Peace Walker managed to get up on its own and sacrifice itself to end it by drowning in the lake, causing the data to short out from the circuits being exposed to water.

Afterwards, the Militaires Sans Frontières returned to Nicaragua to remove the nuclear missile from Peace Walker, in order to avoid another conflict with the natives (the missile was still radioactive and could potentially contaminate the lake, or end up being discovered by terrorists). Kazuhira Miller, MSF's subcommander, then suggested to Big Boss that he place it on Metal Gear ZEKE, otherwise they would need to dispose of it. Although Big Boss hesitated, being taken aback by the suggestion, he ultimately agreed.

Portions of Peace Walker were later fished out by the FSLN headed by Amanda under Strangelove's request during the mid-1970s, this time to retrieve the Mammal Pod to be shipped to the USSR, for use in AI experiments. In addition, Peace Walker's development, in particular the fact that it had been plagiarized from Granin, was indirectly referenced by Ocelot when Huey was proposing to the Diamond Dogs a similar weapon to ZEKE called Battle Gear.[11]

Behind the scenes[]

"King of Snakes," another name for the mythological basilisk, was a name used to refer to Naked Snake in advertising for Metal Gear Solid 3: Snake Eater.

The design of Peace Walker was originally going to be significantly different, resembling Metal Gear REX, and its hangar was also intended to closely resemble REX's hangar on Shadow Moses Island.

The player first fights Peace Walker in its bipedal form, while utilizing the Reptile Pod; its movements resembling those of a theropod dinosaur. After the Mammal Pod had been installed, it walked on four legs, much like a quadrupedal mammal.


Basilisk Play Arts Kai model.

The Play Arts Kai model for Peace Walker is referred to as Basilisk.

Peace Walker, identified as Basilisk, was also supplied two sets of AI voices for DLC from the game. The first supplied it with a more human voice that was voiced by Lori Alan/Kikuko Inoue. The second, released in Japan only, supplied Basilisk with a voice possessing a Nagoya Dialect.

"BASILISK: Human Voice
This is the alternate voice data for the "BASILISK" AI weapon. (V.O.: Lori Alan)
When downloaded, this will change the voice for the respective AI weapon from EXTRA OPS.
―BASILISK: Human Voice DLC PSN description for the International release of Metal Gear Solid: Peace Walker
"Basilisk Human voice version
AI weapon "Basilisk" another voice (CV: Kikuko Inoue)
If download, an appropriate AI weapon's sound of EXTRA OPS is changed.
―BASILISK: Human Voice DLC PSN description translation for the Japanese release of Metal Gear Solid: Peace Walker
"Basilisk Nagoya accent version
AI weapon "Basilisk" Nagoya accent voice version
If download, an appropriate AI weapon's sound of EXTRA OPS is changed.
―BASILISK: Human Voice DLC PSN description for the Japanese release of Metal Gear Solid: Peace Walker

On October 25, 2011, Peace Walker, alongside Chrysalis, were used in a test for the Fox Engine.[12]

Peace Walker (identified as Basilisk) also appeared on the series site's official website under the Versus Battle, where it fought against Chrysalis.

Stealth, Massive H-Bomb, THE Peace Walker
Can Only Go Nuclear in Self Defense
Developed by Strangelove and Otacon’s father, Basilisk contained two AI pods, Reptile & Mammal, with the Mammal’s neurons modeled after The Boss
―Basilisk in Versus Battle

Peace Walker also appears on the Mother Base development game on the Ground Zeroes app, where it acted as one of the developable Metal Gears. It can be unlocked by building a Level 7 Hangar, and costs 500 salvage to create. A custom version is also unlockable by obtaining 24k+ points on Hard Mode Intel Operative Rescue while connected to the app.


During the second battle with Peace Walker, the mecha will attempt to prepare the countdown for the nuclear strike into Cuba. If Snake fails to stop the countdown, then a Game Over sequence occurs where the missile is shown being launched.

An Extra Ops mission requires Snake to fight an upgraded version of Peace Walker colored in maroon paint. The way it is defeated after taking out its HP is similar to how Pupa, Cocoon, and Chrysalis are defeated (its AI pod being released after jumping out of the AI pod, causing it to launch like a rocket). Also, if the player deals minimal damage to the head, the player can also unlock the Peace Walker head for use on ZEKE.

During the Peace Walker Type II & Peace Walker Custom battles, the Mammal Pod is absent.

While Peace Walker is standing on two legs, you can hit the Mammal Pod with a rocket launcher


Ordinary/Type II[]

  • "Freeze!" (when using poison beam)
  • "Flamethrower engaged!" (when using flamethrowers)
  • "Face me!" (when roaring)
  • "Launching S-Mines" (when using cluster bombs, also when walking)
  • "Firing rocket launcher" (when launching rockets)
  • "Firing Drill Missiles" (when launching drill missiles)


  • "Poison Beam!" (when using poison beam)
  • "Flamethrower!" (when using flamethrowers)
  • "Bring it on!" (when roaring)
  • "Try this on for size!" (when using cluster bombs, also when walking)
  • "How do you like this?" (when launching rockets)
  • "Die!" (when launching drill missiles)
  • "It can't be! (when crush the player and it's stopped) 



See also[]

Notes and references[]

  1. ^ Metal Gear Solid: Peace Walker, Kojima Productions (2010).
    Miller: How much does that thing weigh? // Huey: 500 tons.
  2. ^ Metal Gear Solid: Peace Walker, Kojima Productions (2010).
    Chico: I opened my eyes and saw an enormous shadow. Must have been 30 Vara [82 ft] at least. ... It was walking on legs as big as trees.
  3. ^ Metal Gear Solid: Peace Walker, Kojima Productions (2010).
    Briefing Files > Chico > Geographical Info > Supply Staging Point
    Chico: But you might run into el basilisco... Keep your eyes peeled, Snake.
    Snake: An 80-foot-tall walking behemoth... The CIA's new weapon?
  4. ^ a b c
  5. ^ a b
  6. ^ Metal Gear Solid: Peace Walker, Kojima Productions (2010).
    Huey: Peace Walker's estimated top speed on level terrain is 25 miles an hour.
  7. ^ Metal Gear Solid: Peace Walker, Kojima Productions (2010).
    Briefing Files > About this [Destroy the Barricade] mission > Miller > Basilisco
  8. ^ This was shown during Hot Coldman's speech about the false data, where Strangelove, inside a van with a satellite dish on top, was shown inputting the data onto a computer terminal.
  9. ^ Metal Gear Solid: Peace Walker, Kojima Productions (2010).
    Huey Emmerich: Are you sure you're feeling all right? (scene flashes to an image of the mystery device)
    Big Boss: Anyway, long story short, the butterfly got away. So how about it, doc? Did you make that big "butterfly" too?
  10. ^ Metal Gear Solid: Peace Walker, Kojima Productions (2010).
    Briefing Files > Huey > Peace Walker > The Reason for Launching a Real Nuke
    Big Boss: Why is Coldman gonna launch a nuke? If all he wants to do is prove the AI retaliation system works, he doesn't need to put a live warhead on it. // Huey Emmerich: I agree. He could demonstrate the system by launching the missile alone - without a warhead. I asked him the same thing at first. He said there was no point in using a dummy missile... That it'd take an actual nuclear launch to deter potential enemies. Launching the real deal gives him a leg up in negotiations with Langley. That's what he's really after.
  11. ^ Metal Gear Solid V: The Phantom Pain, Kojima Productions (2015)
    Huey Emmerich: This. // (Hands Snake the blueprints for the weapon) // Emmerich: It's a variable multi-legged tank, a spin-off of Metal Gear technology. // Revolver "Shalashaska" Ocelot: Big fan of "spin-offs," isn't he? I hear he borrowed from the Soviets in Costa Rica, too.
  12. ^