He initially uses the codename "Major Tom" during the Virtuous Mission, a reference to one of three tunnels dug by Allied P.O.W.'s in the movie The Great Escape. However, after the failure of this mission, Zero informs Snake that, upon watching the film again, the tunnel "Tom" was one of the two discovered by the Stalag guards. He then asks that Snake simply refer to him as "Major Zero" from then onwards, believing that his mistake had brought bad luck upon the Virtuous Mission.
During both missions, it is revealed that Zero is very fond of tea and scones, in stereotypical British fashion. He is also an avid fan of James Bond, and is quick to launch into an angry tirade when Snake laughs at the idea of a globe-trotting, gadget-using spy who places himself in harm's way. Zero also despises coffee, referring to it as "mud," and tends to bore Snake with tales of his experiences in the service and comparisons of professionalism between Snake's operational conduct and his own former SAS unit. Zero also believes that at some point in his life he was abducted by aliens.
In Metal Gear Solid: Portable Ops, he and Snake are blamed for the FOX unit's revolt and Zero is supposedly kept in captivity in a military prison, accused of treason. However, he is "exonerated" after the mission's success and greets Snake on his return home.
In Metal Gear Solid 4: Guns of the Patriots, he is revealed as the original founder of the Patriots (noted as the "man with the same codename as Null" in MPO), who recruited the other five members to join him. He was actually in collusion with Ocelot during the events of MPO. By the time of MGS4, he is essentially brain-dead and in a vegetative state due to his advanced age of 105, confined to a wheelchair with a life support system. Big Boss euthanizes him by cutting off his oxygen supply.
Para-Medic earned the nickname "Quack" during her employment as a doctor due to her penchant for chatting for long periods of time.
She is generally repulsed by Snake's blatant disregard for selecting suitable plants and animals, which would generally be classed as "people food." This is most apparent when Snake is deciding whether or not he should use the Spetsnaz guard dogs, The End's parrot, and The Boss' Andalusian horse as a source of food. She also acts in an overprotective manner towards Snake throughout the game.
Para-Medic also loves movies, particularly science fiction and horror titles, and often mentions them to Snake after saving the game or when something reminds her of them. For example, Snake's helmet and breathing apparatus used during the HALO jump immediately preceding the Virtuous Mission remind Para-Medic of the film The Fly. Para-Medic can also be considered a "Japanophile," as she seems completely smitten with the country, its culture and its fads, such as "Kerotan" and "GA-KO." She later created the first paramedic system in Seattle in 1970, and the modern usage of the name supposedly coming from her.
Para-Medic returns in Metal Gear Solid: Portable Ops as a recruitable character in the single player campaign. Metal Gear Solid 4: Guns of the Patriots reveals that Para-Medic is one of the six founding members of the Patriots and was the one who initiated the Les Enfants Terribles project that led to the creation of Big Boss's clones. She is also revealed to be Dr. Clark, the scientist who was killed by Gray Fox prior to the events of Metal Gear Solid. This causes an inconsistency with the English version of Metal Gear Solid, which referred to Dr. Clark as a male (the character had no defined gender in the Japanese version). The Metal Gear Solid 4: Database covers this inconsistency by explaining that Dr. Clark was reclusive and never personally met her staff, leading Naomi to assume she was male.
Sigint is the youngest member of the team, being only 24, and believes himself to be the only sane member of the unit. Sigint tends to become easily irate, criticizing Snake on various occasions for his strange and conspicuous choices in clothing and face paint (one memorable example being when he questions Snake on his use of a cardboard box for a disguise). He is also the character most responsible for breaking the "fourth wall", as well as attempting to explain away things that seem odd or not right. For example, playing the game a second time with The Boss' Patriot pistol will result in Sigint asking Snake how he managed to get his hands on the gun if The Boss is still alive and using the weapon herself. Snake will reply that Sigint worries too much about "the details." He developed the Active Sonar, the Motion Detector, the AP. Sensor, and the EZ Gun (available only on the Very Easy difficulty setting or getting it by catching all 47 edible items and species of animals and plants in the game in any other difficulty) which Snake uses, as well as the Raikov mask (a reference to the main character of Metal Gear Solid 2: Sons of Liberty). In 1965, Sigint joined DARPA and takes part in the development of ARPANET. In a radio conversation, he reveals to Snake that he suffered racial discrimination in his former jobs, because he is black, and that Major Zero recruited him without any prejudices.
He would later reprise his role as Snake's support in Metal Gear Solid: Portable Ops. He is a recruitable character in the single player campaign. Metal Gear Solid 4: Guns of the Patriots reveals that Sigint is one of the six founding members of the Patriots. He is also revealed to be Donald Anderson, the DARPA Chief from Metal Gear Solid, a minor character who was murdered by Revolver Ocelot and impersonated by Decoy Octopus.
The Boss (a.k.a. The Joy) is a legendary American soldier, founder and leader of the Cobra unit, and is known as the mother of the U.S. special forces. According to the Metal Gear Solid 4: Database, she was born in 1922. She is known in Russia as Voyevoda, literally meaning The Warlord. In June 1944, during World War II, she led the Cobra unit to victory at the Battle of Normandy. She was pregnant at the time with a baby fathered by The Sorrow and gave birth to a baby boy on the battlefield via a messy caesarian section that left her with a long, snaking scar across her abdomen. The baby was taken by the Philosophers and would later grow up to be Revolver Ocelot.
The Boss is Naked Snake's mentor; he saw her as a mother-figure and she saw him as the son she never got to raise. The Boss and Snake took on numerous missions for the ten years they were together, and the two of them are responsible for creating CQC. During the events of The Virtuous Mission, The Boss defects to the Soviet Union and joins Colonel Volgin's renegade faction, becoming the lead instigator in the events that led to Operation Snake Eater. She serves as one of the game's main antagonists and as the final boss. Shortly after returning to the States, Snake learns from Eva that the Boss had not defected, but was actually undercover and had willingly and knowingly sacrificed her life and reputation to benefit America.
The Boss officially hands over her title to Naked Snake at the end of Metal Gear Solid 3, saying, "There's only room for one Boss and one Snake." (A rewording of Liquid Snake's line near the end of Metal Gear Solid, "There's only room for one Snake and one Big Boss!") However during the events depicted in Metal Gear Solid: Portable Ops, Snake still refuses to go by the title of Big Boss as he feels he has not yet surpassed The Boss as a warrior. Hence he refers to himself by his old codename, Snake, for the duration of the game.
Despite her death, the Boss' ideal (or what is perceived of it) greatly influenced the events of the world of Metal Gear. Her ideal formed the basis of the Patriots, until Big Boss decided that the Patriots no longer follow her ideals, and formed Outer Heaven and Zanzibar Land. In Metal Gear Solid 4: Guns of the Patriots, Big Boss remarks sorrowfully that her death has greatly affected him to that point, going as far as to comment that the day she died is the day he died as well.
The End is a member of the Cobra unit with exceptional sniping skills, born in the early 1860s, and the only member of the Cobra unit without an emotion-based codename, though it is explained in the game that it signifies "true oblivion. The End uses stun grenades and a modified Mosin-Nagant rifle converted to fire sedative rounds. The End can also become "one" with the environment, flora and fauna included. He apparently can summon the spirits of the "holy forest" he waits in to revive his stamina through directed sunlight. His pet parrot (an Alexandrine parakeet) alerts him to Snake's presence acting as a spotter of sorts, and calls him "Grandpa". If Snake is defeated by The End, he will simply carry the unconscious protagonist back to the Graniny Gorki Laboratory prison cells, leave the door unlocked, return to his position and await Snake's inevitable return; he is the only member of the Cobras that will not kill the player under any circumstances. If the player does not wish to struggle through this battle, the player has two options: the player can simply turn off the console and wait for seven days (or set the system clock a week ahead). This will result in a secret cutscene in which The End has died of old age, while Snake feels that he has disappointed The End in his final moments. The second option is when the player sees The End getting pushed in a wheelchair during a cutscene. The player can use the sniper rifle and shoot The End in the head before he is fully wheeled through the door. It is advisable to move out of the way, seeing as a wheel from the wheelchair will inevitably come flying at Snake's head.
The End was based on "Old Boy", a concept character originally created for Metal Gear Solid 2: Sons of Liberty. Old Boy was an ancient soldier who had, among other things, been a Nazi Third Reich Generalfeldmarschall, and a mentor to numerous soldiers, including Big Boss. The character was discarded early during development, but his concept was reused in Metal Gear Solid 3: Snake Eater.
The End was named the fourth greatest boss of all time by Electronic Gaming Monthly in their 196th issue.
The Fear is a member of the Cobra unit known for his superhuman speed and agility, as well as his freakish, fearsome appearance. His elbows are double jointed, and he has a long, lizard-like tongue, forked through surgery, that he can use to grasp objects. Capable of dislocating his joints at will, he is able to crawl, walk on water, flip, leap extremely quickly in the manner of a spider, and also climb and jump around in trees with ease. He mainly uses a crossbow in battle, coating his bolts in the venom of the Brazilian Wandering Spider, setting them on fire or even outfitting them with explosives. He uses a variety of wires and ropes to enhance his mobility. On top of his incredible agility, he also uses Stealth camouflage to make himself nearly invisible; as a result, he is incredibly difficult to hit. He is also an expert in booby traps; the forest where Snake fights The Fear is riddled with them. The Fear is killed in a skirmish with Snake following his departure from Granin's lab.
The Fury is a pyromaniac and former Soviet cosmonaut. He utilizes a flame-resistant Soviet space suit in conjunction with a jet pack and a powerful flamethrower, both of which are powered by liquid rocket fuel UDMH. His codename reflects the unmitigated fury he feels towards the world while he is fighting.
His fight with Snake commences in the concrete environment of the underground tunnel leading to the Groznyj Grad fortress. The ensuing battle is fought in a dark, damp surrounding, with the two combatants attacking between long paths of concrete and pillars. The following demise of The Fury produces two projectiles of fire that fly through the air destroying the scenery. Right before his death, he has a flashback in which he is still in space and returning to Earth, causing Snake to experience the vision as well, only as a reality (the two fire projectiles).
The logo (БEИ) The Fury has on his helmet is BEǏ written in Cyrillic letters, and stands for Belarus in the GOST 7.67 standard for country codes. It also resembles a verb "to strike" (бить) in imperative mood (бей or БЕЙ) in Russian.
The Pain has the ability to control hornets at his will, through the buzzing of a queen bee that he keeps in his backpack. Apart from his hornets, The Pain is also equipped with a Tommy gun and grenades, using his hornets in conjunction with these weapons. He also uses his hornets to shield himself and create the form of a body double to confuse and draw his opponents into the open.
Throughout his meeting with the protagonist, he conveys a desire of wanting Snake to feel the pain that he has endured. Despite his rather large size, The Pain is remarkably swift and agile, making him difficult to corner in combat. He wears a balaclava to mask his disfigured appearance caused from his numerous hornet stings.
The Pain raises Bullet Bees inside his body which attack by going inside the victim's body and attacking the insides of the victim.
The Sorrow was a powerful spirit medium and a former member of the Cobra unit who used his psychic powers to aid his fellow soldiers on the battlefield. He was romantically involved with The Boss and is revealed in the course of the game to be the father of her child Ocelot. After the ideological rift created by the Cold War loyalties changed with he and The Boss each taking their respective sides. Later, he sacrificed himself for The Boss when they met on a battlefield, via a bullet through his left eye, after the Cobra unit disbanded. He makes many hidden appearances (in ghost form) throughout the game's cut scenes although he can only be seen in first-person view. Towards the end of the game, when the clock is counting down to a massive explosion of rocket fuel and C3, The Sorrow can be seen in a number of cut scenes holding up a sign displaying the amount of time left.
Since The Sorrow is already dead at the time the game begins, Snake does not face off against him in a traditional physical fight. Instead, he meets him in the spiritual realm after jumping off a waterfall. The Sorrow cannot be killed in the battle since he is obviously already dead. Instead Snake must wade through a river swarming with the spirits of all the men whom he has killed, while dodging the attacks of The Sorrow, who twitches violently in mid-air in front of him.
The number of ghosts that appear in this segment is directly proportional to the number of people the player has killed in the course of the game; hence, if the player does not kill any unnecessary targets, only the other Cobra unit members will appear to attack Snake. The dead soldiers that Snake encounters along the river all showcase the methods used to kill them, ranging from their throat being slit and blood spewing out, their head being bent backwards as a result of having their neck snapped, to a vulture flying around their head and pecking away at their flesh. Snake eventually reaches The Sorrow's body at the end of the river. When Snake makes it to the Sorrow and touches him, he 'dies'. Using a Revival Pill will resume the story, however, if you take this path rather than avoiding the scenario, Snake will have a special camouflage, which renders his footsteps completely silent and gains back stamina if he chokes an enemy, in his inventory, given to him by The Sorrow as a gift for reaching the end of the river.
At the end of the game when Snake kills The Boss, the player can see the ghosts of both The Boss and The Sorrow materialize and then fading away into the afterlife using first-person view during the following cut-scene.
In Metal Gear Solid 4, after defeating Screaming Mantis, Psycho Mantis appears, but is taken back to the realm of the dead where he belongs by the Sorrow who makes a brief appearance repeating the same line to Snake that he did to The Boss as he died before disappearing. The Sorrow can also be seen as one of the dolls held by Screaming Mantis, which she uses to control the dead bodies of fallen soldiers. When the Sorrow Doll fires ghosts, it says in a high-pitched voice, "Sad... so sad", a line he commonly used in Snake Eater.
Having illegally acquired the Philosophers' Legacy from his father's money-laundering activities, he now funds the development of the Shagohod, a nuclear equipped tank which he plans to use to win the Cold War for the Soviet Union. Volgin's body carries an electrical charge which he uses in conjunction with his fighting style, able to electrocute people and things as well as using it to manually discharge rifle rounds without using a gun. This ability is demonstrated both during Snake's boss battle and during cut scenes in which Volgin obliterates objects by discharging four 7.62x39mm rounds held in between his fingers when making a fist. He is also an extremely strong man even for his large size. The red suit Volgin wears under his jacket features the same logo (БEИ) on the shoulder as The Fury has on his helmet: it is BEǏ written in Cyrillic letters, and stands for Belarus in the GOST 7.67 standard for country codes, or for a derivative form of "to strike" in russian. It is unknown whether his powers are supernatural or if they're caused by the suit he wears.
Not much is known about Volgin's personal life, except for his perverse sexual tendencies. He has taken lovers of both men and women, Major Raikov and Tatyana (EVA) specifically, and all attest to his extreme love of sadomasochism.
Volgin is constantly suspicious of everyone in his domain, which drives him to beat several people to death during the course of the game. He also massacres numerous members of his own faction during the Shagohod chase and uses an American made Davy-Crockett miniature nuclear warhead on a weapons facility. Volgin also chants the phrase "Kuwabara Kuwabara" (a traditional Japanese mantra to ward off lightning and ghosts) at the sight of rain. Ironically, the single time it begins to rain and he fails to chant the mantra, he is struck by a bolt of lightning summoned by the Sorrow--fatally wounding him and setting off each individual bullet on the ammunition belts he was wearing at the time, making for a slow and torturous death.
Volgin is briefly mentioned in Portable Ops, where it's revealed by Gene that Volgin was actually manipulated by the director of the CIA (The deviously cunning strategist that Gene mentioned) into firing the American-made Davy Crocket into Sokolov's lab and framing The Boss for the act. In Metal Gear Solid 4: Guns of the Patriots, EVA reveals that the CIA planned The Boss's death because they feared her charisma.
Volgin could be seen as an embodiment of all the COBRA Unit's members' emotions. He inflicts great pain, instills fear in his own men, enjoys obliterating his enemies, is easily irritable, he enjoys battle and his position is one of great authority (taking traits from The Pain, The Fear, The End, The Fury and The Boss, respectively).
Sokolov defected to the States secretly, however America and the Soviet Union agreed that in return for the Russians removing their missiles from Cuba, America would send Sokolov back to the Soviet Union. Rescuing Sokolov is one of Snake's primary objectives in the game. However, Snake's initial attempt to save Sokolov during the "Virtuous Mission" fails.
In "Operation: Snake Eater", Sokolov is taken to Groznyj Grad to finish the Shagohod. He gives the weapon data to EVA, and is later rescued by Snake. He refuses to leave, stating that no matter where he goes, he will be used to create weapons of mass destruction. He also asks Snake to watch over his family, which is in the CIA's custody. When Volgin discovers Snake, he beats Sokolov to death.
Despite his apparent death in Snake Eater, it is revealed in Metal Gear Solid: Portable Ops that he survived and was put in a prison camp in Russia. Gene rescued him and helped him defect to the United States to see his family. He joined Gene's research team to design Metal Gear. He provides information to Snake as an anonymous informant named "Ghost" or "Prividenyie".
Ocelot (real name:Adamska) is a GRU Major who leads a special unit within Spetsnaz known as the "Ocelot Unit". He first encounters Snake during the Virtuous Mission, where he is subdued in front of his subordinates. During Operation: Snake Eater, Ocelot attempts to challenge Snake to a rematch and gradually begins to respect him. In the end of the game, he is revealed to be a double agent, reporting not only to the KGB, but to the Director of CIA as well.
His idea is rejected by Volgin in favor of Sokolov's Shagohod, causing a rivalry between the two in Granin's mind. He meets Snake in his office while in a drunken stupor and threatens to send his plans to his American friend; the grandfather of Hal 'Otacon' Emmerich. Tatyana a.k.a. EVA gives him a pair of prototype K.G.B. transmitter shoes, which are discovered by Volgin and Ocelot after he is later beaten to death by Volgin, who suspected Granin of being a mole. At the end of the game Ocelot tells the head of the CIA that he found the plans for Metal Gear and that it could prove to be a useful weapon one day soon. Ironically, his rival Sokolov would go on to help build one of the first Metal Gear prototypes.
In the game, Granin assists Snake because of the compliment made about his shoes. He gives Snake the key to progress farther into the game by opening a locked warehouse door. Later, EVA contacts Snake and wonders how he has gotten past the locked door. He admits that Granin gave him the key. This leads EVA to wonder why Granin assisted him, with Snake leaving it to Granin's drunkenness.
Granin is later killed by Volgin, as Snake watches through binoculars from a cliff above Groznyj Grad.
He may also share some sadistic tendencies with Volgin. A conversation with EVA reveals that he enjoys punching his subordinates in the face for no reason. When Snake questions this behavior, EVA explains it by saying, "Raikov's just that kind of guy."
Raikov also has a romantic relationship with Volgin, although it is only implied. He is also the only character Volgin actually likes. In fact, during Snake's boss battle with Volgin, if the player immediately dons the Raiden face mask (in the player's inventory at the start of the game), Volgin will drop to his knees in disbelief, leaving him vulnerable to an initial attack (although any repeated attempt of this trick will result in Volgin simply attacking with disgust).
Snake can choose to knock out Raikov or kill him in order to steal his uniform and gain access to the room where Sokolov is being held. If Snake chooses to kill Raikov, he will reappear later in the game in his thong as a ghost, covering his crotch with his hands, a reference to a part of Metal Gear Solid 2: Sons of Liberty where Raiden must sneak naked.
In Metal Gear Solid 3: Subsistence's online mode, Raikov is a playable character who heads up the GRU unit. After the end of each round the player in the GRU unit with the highest score becomes Raikov. Raikov's special is a CQC move in which he grabs the crotch of his opponent which causes an instant stun. He also cannot be distracted by pornographic magazines.
Raikov returns in Metal Gear Solid: Portable Ops as a recruitable character in a side mission.
In the "Mesal Gear Solid" minigame featured in Ape Escape 3, Snake was sent to stop the release of "Mesal Gear" (the word "Mesal" is a portmanteau of "metal" and the Japanese word for ape, "saru") but was captured by Pipo Ocelot. With the protagonists of Ape Escape (Spike, Jimmy, Kei and Yumi) out to summer camp and the Monkey Net destroyed, Dr. Tomoki downloads the battle data of Snake into a monkey, turning him into Pipo Snake. Snake now must infiltrate the headquarters of Pipo Ocelot to save S.Snake and the world from Mesal Gear's "Lazy Cannon".