Liquid Snake

Liquid Snake, commonly referred to as Liquid, was the former squad commander of High-Tech Special Forces Unit FOXHOUND, and the twin brother of Solid Snake.

Liquid was one of the "Sons of Big Boss," created as part of the Les Enfants Terribles project, along with his clone brothers, Solid Snake and Solidus Snake. Liquid was led to believe that he was created in order to express Big Boss's "recessive genetic traits," and as such, was inferior to Solid Snake. Because of this, he held a strong resentment towards his twin brother, who supposedly expressed "superior" genes, and wished to defeat him in combat, reclaiming what he felt was his birthright, and thus proving his superiority.

Possessing an IQ of 180, Liquid spoke seven languages fluently, including English, Spanish, French, Malay, and Arabic, the last of which he spoke like a native. He was almost an exact double of Solid Snake in terms of appearance, with the only distinguishable feature being his darker skin tone and fair hair color, due to the environmental conditions in which he spent part of his life. He also had a tattoo on his left arm, which resembled the Rod of Asclepius, but with a sword in its place.

Background
An adult Liquid Snake was foreseen in Elisa and Ursula's prophetic vision in 1970, as the son of Big Boss that would "bring the world to ruin."

Liquid was born in 1972, along with his twin brother, Solid Snake as a result of "Les Enfants Terribles," a secret government project designed to create the perfect soldier, using the genes of the "Greatest Warrior of the 20th Century," Big Boss.

Using the process of somatic cell nuclear transfer, eight clone embryos were created by inserting Big Boss's DNA into enucleated egg cells, donated by a healthy Japanese woman. By utilizing the Super Baby Method, the embryos were then implanted into the womb of a surrogate mother, with six of the babies eventually being aborted to promote growth in the remaining two.

The two clones were also modified on the genetic level, with one clone expressing Big Boss's dominant genetic traits, and the other, his recessive traits. Nine months later, the twins were born, who would later receive the codenames of Solid Snake and Liquid Snake. A third clone was also later created, known as Solidus Snake, who inherited an identical genetic code to Big Boss. Liquid was later led to believe that he was the result of Big Boss's "inferior" recessive traits, and would inform an unknowing Solid Snake as such.

Early life and career
Liquid was raised in the UK shortly after birth. His real name was also heavily classified to the extent that even someone among the highest levels of the military chain of command was forbidden to know it. In 1974, Cipher decided to use Solid Snake and Liquid Snake as an insurance policy against Big Boss, should he continue to oppose the organization.

Liquid became the youngest person to serve in the Special Air Service, at the age of 18, having excelled in parachuting, rapelling, scuba-diving, free climbing, as well as the use of military small arms and combat vehicles/submersibles. During the Gulf War in Iraq, he was assigned to an SAS unit to track down and destroy mobile Scud missiles. In truth, he infiltrated the Middle East as a sleeper agent for the British Secret Intelligence Service, but he was taken prisoner by the Iraqis and went missing. Because of his status as a prisoner of war in Iraq, he also never got a chance to enter Century House. In 1994, he was rescued by the U.S. Government. After Solid Snake "killed" Big Boss in Zanzibar Land, Liquid's hatred for Snake grew even more, since he had been denied the chance to exact his own revenge, due to his belief that Big Boss had undergone the Les Enfants Terribles project willingly, and "chose" Liquid to be the "inferior" clone. Liquid Snake joined FOXHOUND in the year 2000, after Solid Snake and Roy Campbell had already retired from the unit. After Liquid joined, he became FOXHOUND's field commander, reinstated the old codename system, with the addition of personal identifiers, and reorganized the unit to be as small as possible so as to allow it to be an elite unit.

In 2005, Liquid's FOXHOUND subordinate Revolver Ocelot, convinced him to launch an insurrection against the U.S. Government, during a weapons testing exercise on Shadow Moses Island. Liquid and Ocelot, along with the other members of FOXHOUND, and the Next-Generation Special Forces seized control of the island's nuclear weapons disposal site, and the newly-developed Metal Gear REX. Calling themselves the Sons of Big Boss, the group took DARPA Chief Donald Anderson and ArmsTech President Kenneth Baker as hostages, and threatened the White House with a nuclear strike unless Liquid's demand was met: the body of Big Boss. The incident was deliberately brought about to coincide with the signing of the START III Accord between the U.S. and Russia: exposing REX's existence would put the signing of the treaty in jeopardy, erode confidence in America’s commitment to non-proliferation, and create international turmoil.

After Donald Anderson died during interrogation, Liquid arrived at a setback, having failed to learn the Chief's activation code for REX. Unable to back up his threat of a nuclear strike, Liquid had Decoy Octopus disguise himself as an imprisoned Anderson, to await rescue from U.S. forces. Liquid anticipated that his clone brother Solid Snake would be sent in to eliminate the terrorist threat, and intended to trick him into activating REX for them, as a backup plan. Along with Octopus's duplicity, Liquid arranged for McDonell Benedict Miller to be murdered at his home, so that he could assume the role of Snake's former mentor and influence his actions via Codec, after tricking Colonel Campbell into allowing him onto the mission support staff.

Alerting the Genome Soldiers of Solid Snake's imminent arrival on the island, Liquid headed out to intercept two F-16s that had been launched by the Pentagon as a diversion. Using a Hind D gunship, provided to him by the Gurlukovich Mercenaries, Liquid successfully shot down the two fighters with his uncanny piloting skills. He then issued a threat to the U.S. Government, warning that he would launch the nuke should they attempt a similar assault. Liquid then made radio contact with Snake, while impersonating McDonell Miller, and offered his support to the unassuming operative. However, Liquid's plans were further complicated when Decoy Octopus unexpectedly died from unknown causes, after coming into contact with Snake. When the ArmsTech President died under similar circumstances, Liquid set out to discover the cause of the mysterious deaths. Nevertheless, he ordered Ocelot and Vulcan Raven not to kill him, wishing to further see what Snake was capable of.

When Snake was later captured by Sniper Wolf, Liquid intended to obtain a DNA sample from him, in order to learn more of the Genome Soldiers' various mutations. After Snake awoke from unconsciousness, Liquid introduced himself to his brother, meeting him face-to-face for the first time. He then gave the order to continue REX's launch preparations as planned, due to U.S. government's lack of response to his demands. He suspected that they must have an ace up their sleeve, and that there was may be a spy among his ranks, questioning the motives of a mysterious ninja, who had managed to kill twelve of his men. He left Ocelot to interrogate Snake, but warned him not to make the same mistake as he did with the DARPA Chief.

After Snake managed to escape from the medical facility, Liquid attacked him with the Hind D as he attempted to cross over the communications towers. The Russian gunship menaced Snake several times before a final showdown on the roof of one tower. Following an intense battle, the Hind eventually went down in flames due to stinger missiles fired by Snake, though Liquid was able to survive. Continuing his impersonation of Master Miller, he then tricked Snake into focusing on his mission support adviser Naomi Hunter as an enemy spy. Utilizing the distraction, Liquid ultimately deceived Snake into activating Metal Gear REX with President Baker's PAL card, since he had been unable to do so without it.

Through information supplied by a spy in the Pentagon, Liquid learned that Decoy Octopus's and President Baker's deaths had been caused by FOXDIE; a DIA assassination virus with which Solid Snake had secretly been infected. He then added a FOXDIE vaccine to FOXHOUND's demands, along with one billion dollars to help correct the Genome Soldiers' mutations, using information gathered from Big Boss' DNA. Deciding to play the superpowers against one another, rather than take them head on, Liquid disregarded Ocelot’s suggestion of Chernoton, Russia, as a target, and instead chose Lop Nor, China, which was the location of a nuclear test site. Since firing a nuke at a major population center would make future negotiations impossible, an attack on a nuclear test site could still be concealed from the public. The U.S. would be forced to confess some of its state secrets to prevent a retaliatory strike from China, after which Liquid could sell the nuclear weapon system to the highest bidder. Not only that, but with Metal Gear REX in his possession, Liquid planned to join forces with the Gurlukovich Mercenaries, and turn Shadow Moses into a new "Outer Heaven." With these vast resources at his command, Liquid would drag the world into a Third World War, fulfilling Big Boss's dream of a world which always had a place for soldiers. Liquid, resuming the disguise as Master Miller, also advised Snake to change the PAL key, although by the time Snake managed to change it to the red PAL key, he almost blew his cover in excitement that Snake was getting close to activating REX, although he summarily covered it up by claiming that he's just excited that Snake's about to succeed in the mission.

After Solid Snake unwittingly activated Metal Gear, Liquid revealed his deception as Master Miller to Snake and locked him within the launch control room. Having no more use for Snake, he released nerve gas into the room, though Snake managed to escape with the help of Otacon. Eventually cornered by Snake, Liquid revealed the existence of FOXDIE to him, and that the Pentagon wished to recover REX and the Genome Soldiers' remains without damage. Expressing his hatred for Big Boss, Liquid told Snake that he intended to destroy their father by surpassing him, and escaped into REX's cockpit to engage Snake in battle. However, with the help of the Cyborg Ninja Gray Fox, Snake successfully destroyed Metal Gear, but is knocked unconscious in the resulting explosion.

Having survived the Metal Gear's destruction, Liquid dragged Snake to the top of REX's remains, and directly threatened the Pentagon via Snake's Codec implant, referring to them as "Patriots." As Snake regained consciousness, Liquid told him that he wouldn't be killed so long as Snake lived, and even with the destruction of REX, his fight was not over yet. He explained to Snake that his ultimate goal was to give soldiers a purpose again, especially since soldiers continued to be abused by hypocritical politicians and their political gambits. He also deduced that Snake, despite his protestations, enjoyed the thrill of battle and would welcome the prospect of a war-torn world, which he intended to create. Liquid then revealed to Snake the history of their own creation, as well as that of the Genome Soldiers, and the reason why they needed Big Boss's remains. He then revealed that while Snake was still unconscious, he had placed a prone Meryl Silverburgh on top of REX as well as wiring her to a timed explosive. With a bombing raid on the facility, ordered by U.S. Defense Secretary, due to commence shortly, Liquid and Snake battled barehanded atop the ruins of Metal Gear. Snake eventually managed to throw Liquid off to the ground far below.

Though it seemed that Snake was victorious, Liquid survived the fall from REX. A car chase ensued as Liquid raced after Snake and Meryl by jeep, who were trying to escape from the impending nuclear strike via a supply tunnel. Using a FAMAS rifle to attack, Liquid was kept at bay by Snake's machinegun fire, until both jeeps crashed at the tunnel entrance, just outside the facility. Just as he was about to kill Snake and Meryl, who were both trapped underneath their vehicle, Liquid suddenly lurched backwards and collapsed to the ground, succumbing to the FOXDIE virus.

Post-Shadow Moses
Revolver Ocelot, the sole surviving member of FOXHOUND, reported the events on Shadow Moses to U.S. President George Sears, for whom he had acted as a spy throughout the entire incident. He informed Sears, a.k.a. Solidus Snake, that it was the inferior clone who had survived, stating that Liquid had wrongly believed himself to be the inferior one right until his death. Liquid's body was later recovered, and his right arm was transplanted onto Ocelot, replacing the one he had lost to the Ninja. Afterwards, Liquid's corpse was put in cold storage inside a facility, only for Philanthropy to later steal it from the facility.

In 2007, Liquid Snake's personality took over the mind of Revolver Ocelot in the middle of his hijacking of Metal Gear RAY, aboard the USS Discovery. "Liquid" made his presence known to Solid Snake, telling his brother that he was "drowning in time," and that he avoided this fate by living on through the transplanted arm. After the hijacking, "Liquid" proceeded to destroy the Discovery, along with the U.S. Marines onboard, before making his escape, almost drowning Snake in the process. However, Snake survived the incident and used Liquid's stolen corpse in an attempt to fake his own death with Liquid's body (sans the right arm). The ruse worked, and Liquid's body eventually ended up interred in Snake's place.

In 2009, "Liquid" anonymously tipped off Snake and Otacon regarding the Big Shell, in order to lure his brother into Arsenal Gear and use his presence to gain full control of Ocelot's body. Apparently, Liquid's personality would often take over Ocelot's mind whenever Snake was in close proximity. Liquid's corpse was later exhumed for DNA testing by Rosemary under Raiden's request. During the Big Shell Incident's climax, Liquid's psyche dominated Ocelot's mind completely and revealed his intentions to destroy the Patriots, using their own spy's knowledge to locate them, he told both of his brothers, Solid Snake and Solidus Snake that he had in fact "chosen" Ocelot as a host for this very reason (but elaborated no more on this). Seizing the original RAY model a second time, "Liquid" crashed Arsenal Gear into Manhattan and then fled in search of the Patriots, though Solid Snake later theorized to Raiden that he was likely acting on false information and would never find them.

In 2014, the persona of Liquid Snake had completely fused with Revolver Ocelot, creating the new entity of Liquid Ocelot. In reality, Ocelot had merely pretended to be Liquid via a combination of nanomachines and hypnotherapy to trick the Patriots, although he did discard the transplanted right arm originally belonging to Liquid and replaced it with a prosthetic in order to restore balance to his psyche. Also, Liquid Ocelot used Liquid's DNA via a DNA chip during his first attempt to hack the SOP system. Atop Outer Haven, Ocelot referred to himself as "Liquid's doppelgänger" to Solid Snake.

Personality and traits
Liquid Snake displayed an arrogant and loud attitude in stark contrast to Solid Snake, who was often more calm and collected. He was an especially adept pilot; as demonstrated by his piloting of a Hind D, an unforgiving and difficult helicopter to fly, during a blizzard when the gunships IR and navigation systems were nonfunctional, especially in combat against two F-16's, as well as pilot it from within the weapons operator's cockpit. Ocelot implies that his adept piloting skills were one of the results of the Les Enfant Terribles project. He would later use the same chopper to combat Snake. Because of his being raised in the United Kingdom shortly after his birth, Liquid spoke with a distinctly British accent.

Liquid was incredibly bitter towards Big Boss for apparently knowingly choosing Liquid to be the inferior one and Solid Snake having what he thought was the superior genes. Although his hatred for them knew no bounds, he was also driven by a sense of connection to his twin brother. His main drive was the belief that he bears all of Big Boss's recessive genes, and that he was born knowing that his brother was superior. He was driven to surpass his genetic destiny, and in essence, his father. However, he never learned the truth that it was in fact he that gained the superior genes, while Snake was the inferior. Therefore, in an ironic twist, it turns out that Snake did what Liquid had set out to do all along, with neither of them ever knowing. In addition, he bore pure hatred towards the Patriots, presumably for their involvement in his creation, as he had hunted them down for some time, and vowed that, after he had settled the score with Solid Snake, he will kill the Patriots in such a manner that will "cause even the [grim] reaper's stomach to turn"

Liquid was somewhat skilled in disguising himself, as evidenced by his deception to Snake and the mission control into unwittingly activating REX with the PAL key. However, he did have trouble maintaining his disguise when excited, as evidenced by his reaction when Solid Snake managed to heat up the key, causing Snake to wonder why "Miller" was feeling oddly happy about it.

Liquid showed an apparent lack of compassion and loyalty to his allies, as well as his enemies, in contrast to his twin brother and father, and only seemed to view them as pawns at best. After Snake defeated Psycho Mantis and Sniper Wolf, Liquid (while disguised as Master Miller), commented on how pathetic and foolish they were for not fighting more effectively. However, he did seem to possess some skewed sense of pride and honor, when letting an unconscious Snake live after the battle with REX, just to fight him unbound, and unarmed in a one-on-one duel (presumably in an attempt to feed his ego). Liquid, despite his evil nature, was shown to be merciful as he let Meryl Silverburgh live when Ocelot offered to kill her though it was most likely because she was useful alive to discourage Snake and Campbell and not out of compassion.

Liquid often displayed high levels of endurance, having survived numerous, seemingly fatal, events throughout Snake's mission to Shadow Moses:
 * He was shot down in the Hind D, the explosion of which Snake could see from the top of the communications towers;
 * During the REX battle, Liquid survived the multiple stinger missile hits on the cockpit, and was still inside REX when it finally blew up. The force of that explosion was sufficient to bodily hurl Snake across the room and slam him into a wall. However, once again, Liquid emerged relatively unscathed, dragging Snake to the top of REX's remains for a final fight;
 * At the conclusion of the brawl, Liquid survived a fall of over 10 meters (40 feet) from the top of REX, when he had claimed beforehand that such a fall would kill even Snake;
 * Immediately afterwards, Liquid gave chase to Snake and Meryl Silverburgh, via jeep, eventually causing both vehicles to crash. Dragging himself from the wreckage, staggering but still alive, he attempted to finish off Snake, but finally succumbed to FOXDIE before he could.

Japanese heritage
Being a somatic cell clone of Big Boss, Liquid Snake inherited mitochondrial DNA from the Japanese egg donor of Les Enfants Terribles. Liquid and Solid Snake were also somewhat aware of their Japanese heritage. During the Shadow Moses Incident, Liquid almost let slip his true identity, while posing as Master Miller, when discussing Snake's and Vulcan Raven's common ancestry.

Unconfirmed history
The Twin Snakes were born as a result of a ninth batch of clones, in Carlsbad, New Mexico.

After being sent to Great Britain after birth, Liquid Snake experienced a harsh childhood where he received an education and combat training courtesy of the MI5. Similar to his father, Big Boss, he was also trained in withstanding torture. By the time of age 13, he experienced several combat situations, and spent time as a mercenary and assassin, having disdain for service in the military. He also had the uncanny ability to disguise himself in a multitude of ways, which earned him a spot on the SIS.

His part Japanese heritage, alongside his knowledge of Arabic, allowed him to pass as half Turkish and half Caucasian during his sleeper agent duties, and used his time as a sleeper agent to quickly create contacts with various resistance fighters among oppressed Kurds and Islamic fundamentalists that were repressed as part of Saddam Hussein's pan-Arabist agenda, to which his contacts acted as the main reason why Liquid was able to remain inside Baghdad long after the beginning of the Gulf War despite the heavy presence of the Mukhabarat (the Iraqi Intelligence Service) agents and counterspies within the al-Amn al-'Amm secret police forces. In addition to the SCUD missile mobile launching platforms' locations, Liquid also uncovered details of mustard gas production as well as the movements of Republican Guard tanks, and filed the reports to coalition forces, who promptly used his information to plan a number of missions.

During the Gulf War, Liquid Snake succeeded in destroying four mobile SCUD missile launchers before Iraqi paratroopers captured him, with even Liquid being unable to comprehend how he was captured easily as he was being transported for the secret police's headquarters in a van with a canvas sack over his head. In addition, Liquid was believed to have been sold out by the SIS to get a new source of information from one of Saddam's closest associates. After being delivered to the al-Amn al-'Amm headquarters, he was subject to the torture of the secret police's interrogation squads. These torture rounds, as well as the interrogation squads' sadistic reactions to rubbing salt into Liquid's wounds under Saddam's command, were what led Liquid to believe that humanity, when absolutely free, were vicious and irredeemably evil, almost similar to beasts. His hatred of having his will constrained to the extent that the only "liberty" that it can be allowed is to live was also stemmed from the brainwashing in the POW camps.

He was then brainwashed by the Iraqi government and assigned to undertake major terrorist activities throughout the Middle East before he was rescued in 1994. During his time of brainwashment, he also set about creating international networks. Upon hearing of the FOXHOUND unit during the 1990s, he expressed intrest in it and dubbed his activities Jackal hunting, which was a rudimentary Middle Eastern equivalent of FOXHOUND. He also developed a resistance to extreme climate temperatures due to his missions in the Arab desert regions.

By the time he became the commander of FOXHOUND, he started suffering mental instability as a result of discovering that the "genes" that he inherited from Big Boss as a result of the Les Enfants Terribles project were apparently recessive.

Behind the scenes
Liquid Snake (リキッド・スネーク) serves as the primary antagonist of the original Metal Gear Solid. He is the only "Snake" whose real name is not revealed in the series, and the only one that has not worn an eye patch (or a similar device). The mission in which Liquid Snake was captured in Iraq bears similarities to one of the mission outlines of a failed SAS operation during the Gulf War, Bravo Two Zero. In the original game, Liquid mentioned that Big Boss had personally told him that he was inferior. This line of dialogue was changed in the remake, Metal Gear Solid: The Twin Snakes, and in the fictional in-game novel In the Darkness of Shadow Moses to stating his belief that Big Boss chose him, knowingly, to be the inferior one, suggesting that the two never met one another.

It remains unclear as to which clone was created to express Big Boss's dominant or recessive traits, since Liquid's exposition on Les Enfants Terribles is contradicted by Ocelot's later report to Solidus, regarding which clone was designated the "inferior" one. The subject of Big Boss's dominant and recessive traits, in regards to the clones' gene expression, is never once referred to again in other games in the series after Metal Gear Solid. A recap of Liquid's dialogue was included in the in-game novel In the Darkness of Shadow Moses, but there is no mention of dominant and recessive traits. However, the dialogue remains essentially unchanged from the original game in the remake The Twin Snakes.

During their confrontation on Metal Gear REX, when Liquid informs Snake about the latter's enjoyment of killing being the reason he returned to Shadow Moses Island, he cited that Snake killed "most of [Liquid's] men." The context it was given left it ambiguous as to whether he was talking about the members of FOXHOUND only or both the FOXHOUND members and the Genome soldiers. However, In the Darkness of Shadow Moses changed the wording to his citing that Snake killed "dozens of [Liquid's] men," implying that he was indeed referring to both the FOXHOUND members and the Genome soldiers.

In character artwork for Metal Gear Solid, Liquid Snake is seen to wear dog tags, though they are not seen in the game itself. However, his wearing of dog tags was included in the remake, The Twin Snakes, in which the player is also given an option to procure the tags if they knock Liquid off the edge of Metal Gear REX. Nevertheless, Liquid will retain them in various following cutscenes.

In the original plot for Metal Gear Solid 2, Liquid was intended to have faked his death from FOXDIE and was also to have been the main antagonist of the Tanker chapter (which was originally supposed to be on an aircraft carrier). However, this, along with most of the original plot, was scrapped due to tensions rising in the Middle East. According to character designer Yoji Shinkawa, Liquid Snake was originally dark haired like his brother (Solid Snake) but it was bleached to blonde by the intense rays of the sun during his time in Iraq.

AbbyShot Clothiers, a company that creates movie and video game-inspired clothing, created a trench coat similar to the one that Liquid wears. It is priced at $399 CAD, $387.03 USD, and £247.38. On a semi-related note, Liquid Snake's attire also resembled that of Colonel Silver, a member of the Red Ribbon Army from the Dragon Ball franchise, who in the anime also shared the same Japanese voice actor as Liquid (Banjo Ginga).

During the 2009 Tokyo Game Show, Hideo Kojima stated that players would discover what caused Liquid Snake to become one of the series' antagonists in Metal Gear Solid: Peace Walker. However, Liquid makes no actual appearance in the game and is only mentioned once, during Kazuhira Miller's secret phone call, as one of the "two sons" of Big Boss. He does, however, make a cameo appearance in the English version of Peace Walker, on the front cover of the Liquid Magazine. This was changed from the real-life Dengeki PlayStation magazine featured in the original Japanese version. The Liquid Magazine featured two lines uttered by Liquid on the cover; "We have no past, no future", in reference to his statement to Solid Snake regarding their creation for the sole purpose of fighting, and "Did you like my Sunglasses", referring to his line when Snake confronts him in the hangar, regarding his disguise as Master Miller.

Liquid Snake appeared as a participant in the Konami-sponsored event E3 Battle, where he defeated Adba Anda from Otomedius in the first round. He will be facing off against Revolver Ocelot in the second round.

"LIQUID SNAKE FIRST APPEARED IN Metal Gear Solid (1998) Former FOXHOUND squad leader and twin brother to Solid Snake."

- Liquid Snake's bio from E3 Battle

Metal Gear Solid
When outside the control room of Metal Gear REX before Snake loses the PAL Card, the player can contact Liquid, who will still answer disguised as Master Miller, even though Liquid will still appear to be sharing a conversation with Ocelot if the player looks at the control room in first person view (at this point, the player is unaware that Miller is really Liquid, and the player cannot look in First Person View while using the Codec. The player can however, use the scope to view Liquid and call Master Miller).

If Snake is killed during the torture session with Ocelot, Liquid will berate Ocelot for "doing it again," referring to Donald Anderson's death.

If Snake fails to defeat Liquid atop REX before the time limit runs out, Liquid will laugh maniacally during the Game Over screen. If the player pushes Liquid off REX in The Twin Snakes, Liquid will drop his Dog Tags.

Super Smash Bros. Brawl
Liquid (along with several other Metal Gear characters) made a cameo feature in Super Smash Bros. Brawl as a mention in a collectible trophy in Super Smash Bros. Brawl. According to the Cardboard Box trophy, Liquid is just as fond of cardboard boxes as his brother and father. He also appeared as a sticker, depicting his Metala Gear Solid artwork, of which, when it is worn, the food effect will increase by 6.

Metal Gear Solid 4: Guns of the Patriots
Killing enough human enemies in Metal Gear Solid 4 will cause Old Snake to recall Liquid’s words to him at the end of Metal Gear Solid ("You enjoy all the killing, that's why!"). The shock from this episode causes Snake to throw up and his Psyche Gauge lowers drastically. Although, if you pause the game after Liquid's speech, then you will skip the vomiting and not lose any Psyche. In Metal Gear Solid 4, Liquid's voice is heard over flashbacks taken from The Twin Snakes.

In Act 4, when arriving at the Supply Route where REX's remains are located, taking a picture of the cockpit area will reveal a ghost of Liquid Snake sitting in the cockpit.

During the opening stage of the final battle with Liquid Ocelot, images of Liquid from Metal Gear Solid flash on the screen, and the "Encounter" music from Metal Gear Solid is played. Liquid Ocelot's attack patterns in this stage are similar to the ones Liquid Snake used in the fistfight atop REX.