Metal Gear Wiki
Metal Gear Wiki
"XOF... kisses and hugs, followed by a big "F" you."

XOF logo.

XOF was originally a covert support unit for its CIA counterpart FOX during the 1960s until becoming Cipher's covert strike force in 1970.[1] During this time, they were led by a heavily scarred assassin known by the codename of "Skull Face." The group's logo utilized an inverted image of the fox that was used by the (then defunct) FOX Unit. During the 1980s, missions of higher priority were assigned to their new special forces team called the Parasite Unit.


Skull Face, the commander of XOF.

XOF was first created by Major Zero as an unconventional support unit to its CIA-counterpart, FOX, where members would secretly provide tactical support and field Intel to FOX Operatives during missions as well as cleaning up after them, making sure that the operatives left no traces that they were ever there. Its overall purpose was to ensure the survival and success of FOX operatives during missions in order for the unit to become a success by any means necessary. While the Major saw FOX as his silver bullet in the world of espionage, he created XOF to act as the recoil for that bullet to make sure that the mission would succeed at all costs. Zero appointed his XO, Skull Face, to be the commander of the elite black ops group. The existence of the unit was highly classified to the point where even the CIA and The Boss herself were unaware of its existence. The unit was first deployed in secret during the Virtuous Mission in 1964, where members of the unit were ordered to provide covert support to FOX operative Naked Snake. After the Virtuous Mission, Major Zero deployed XOF in secret again during Operation Snake Eater to covertly follow, assist, and clean up after Naked Snake during the operation.

In 1970, FOX was disbanded by Zero after he acquired the Philosopher's Legacy in its entirety, although Zero offered Skull Face and his unit the opportunity to become a part of his new organization Cipher, as its black ops strike force - with Zero citing that he "would show America how to spend its money". While their official cover was they remained with the CIA as a counter-terrorism unit, they truly had no connection to Langley and took their orders directly from Zero. During this time Skull Face once again had the rank of Zero's Executive Officer (XO), giving a certain amount of political power within the organization.

Ground Zeroes Incident

Main article: Ground Zeroes Incident

XOF unit in helicopter.

During 1975, a few months after the Peace Walker Incident, XOF were involved in the imprisonment of Cipher agent Paz Ortega Andrade after a Belizean fisherman recovered her from sea and held her for interrogation on behalf of her former employers.[2] Learning that she was the only Cipher agent to ever meet Zero in person since going into seclusion, Skull Face saw it as the perfect opportunity to make his former CO suffer. Needing to interrogate Paz without Zero ever knowing, Skull Face and a detachment of XOF soldiers took command of a U.S. Marine Base named Camp Omega, converting it into a black site.

Warning: The following events occur in the pseudo-historical Side Ops in Metal Gear Solid V: Ground Zeroes; its level of canonicity is ambiguous.

An undercover agent uncovered and likewise relayed to Big Boss that XOF was not actually aligned with the CIA at all.

Side Ops information ends here.

They were frequently stationed at the admin building spending the majority of their time torturing Paz for Zero's location.[3] The XOF later detained Chico, a child soldier in Snake's army, after he was caught by the Marines in an attempt to rescue Paz from the base. Knowing that the young prisoners had information regarding both his worst enemies (Big Boss & Zero), Skull Face saw this as an opportunity to kill two birds with one stone and proceeded to viciously torture both Chico and Paz for information regarding the location of Mother Base and Zero, respectively.

While Chico and Paz attempted to resist Skull Face's torture, he eventually was able to make them submit and got the information he wanted. He proceeded to turn Camp Omega into a staging ground for his attack on MSF's Mother Base, planning to pose as UN inspectors after learning of Mother Base's coming inspection from Chico, who also told him of Huey Emmerich's approval for the inspection. Before leaving, Skull Face visited Chico, and told him "Give my regards to your Boss, when you get home." Anticipating the arrival of Big Boss at Camp Omega, the unit commenced their "Trojan Horse" operation on Mother Base under the guise of a UN nuclear inspection, having detonated covertly planted C4 packed on the bases struts, causing the facility to fall off balance.

During the assault, Skull Face escaped with Huey Emmerich to their facility in Afghanistan, knowing his involvement in the Peace Walker project and intended to use him to develop his own Metal Gear for the XOF. While the XOF were success in destroying Mother Base and the majority of its staff, Big Boss, Kazuhira Miller, and a medic were able to escape. To avoid raising suspicion and to keep their existence secret, Skull Face and presumably others removed the XOF logo from the choppers and ordered his men to remove their XOF patches and disposed of them to the wind once airborne, although nine managed to remain on the base (one landing among Big Boss's gear around the time he was scaling the cliff). The Marines stationed at Camp Omega also witnessed this, although some believed them to be leaves.[4] The Marines also had no idea who XOF were but did have some suspicions about them.[5][6][7][8][9][10][11][12]

Hostile takeover

Having believed that Big Boss was taken care of, Skull Face initiated the next phase of his plan to strike against Zero. From his interrogation of Paz, Skull Face discovered that Zero had been holed up in a heavily fortified apartment complex in Hell's Kitchen in New York City. The building was filled entirely with Cipher operatives who lived there under the guise of tenants and were given one strict directive, protect Zero at all cost. To make things more complicated, Zero himself lived in a secure penthouse with no windows, with the only entrance being hidden stairs leading to his secret floor, located at the top of the building.

With little ways of taking Zero out directly, Skull Face planned to use a replica of an old military pin that held significant value to Zero and laced it with a parasite strain that would slowly put Zero into a vegetative state.

Shortly after Zero was immobilized, Skull Face proceeded to take control of the majority of Cipher's resources and operations and absorbed them into XOF, making them significantly stronger though XOF likely had no idea their orders came from Skull Face and probably didn't know the organization was a part of Cipher at all. What remained of Cipher was left under the control of Donald Anderson by the request of Zero.

Phantom Pain Incident

See also: Hospital Escape and Phantom Pain Incident

In 1984, Skull Face had a detachment of XOF soldiers deployed into Cyprus for a search and destroy mission after learning the whereabouts of Big Boss. Their primary objective was to assassinate Big Boss by any means necessary, while their secondary objective was to eliminate all traces that they were there. Among the elite operatives involved in the operation was the elite XOF assassin Quiet. Although the presence of the powerful psychic Tretij Rebenok and the demonic apparition of Colonel Volgin, now known as the "Man on Fire" arrived at the hospital shortly after XOF, making them an unknown factor in their mission to kill Big Boss. Aware of Rebenok's pyrokinetic abilities, XOF soldiers had equipped themselves with oxygen tanks and rebreathers in anticipation for Rebenok and the man on fire. Quiet was tasked with eliminating Big Boss upon locating him in the hospital, but was thwarted by interference from another patient in the ward. The rest of the XOF's forces were tasked with eliminating all the hospitals patients and work personnel. The appearance of Tretij Rebenok and the Man on Fire created complications for XOF, with the latter destroying a large amount of XOF's vehicles and troops in his wake, and ultimately resulting in helping facilitate Big Boss's escape from XOF during the chaos. While they failed their primary objective in eliminating Big Boss, the XOF suceeded in eliminating all traces of their involvement in the operation. After learning of the Man on Fire and Tretij Rebenok in this incident, Skull Face used his rage to direct Tretij Rebenok and in doing so gained control over the child himself and the Man on Fire.

XOF continued to operate as Skull Face's personal strike force, furthering his grand scheme of "ethnic liberation" through various covert operations. It was during this time that Skull Face deployed the Parasite Unit for various missions of high priority. Eventually, XOF was tasked with taking over and guarding the secret Soviet research station OKB Zero, while Skull Face began his final preparations for unleashing the English strain of the vocal cord parasite. However, Venom Snake managed to evade the extensive XOF presence at the facility and make contact with Skull Face. XOF's mission was almost complete until Tretij Rebenok, acting under a new affinity, activated Metal Gear Sahelanthropus against Skull Face and his forces. In the ensuing chaos, with two XOF troops having to drag Skull Face to safety due to his being too shocked at the existence of someone with a higher lust for revenge against Snake than even himself or the Man on Fire to even attempt to evacuate the premises by himself, XOF received heavy casualties and lost their commander Skull Face.

Despite this, XOF continued to exist under new leadership, their orders arriving though the same channels.[13] At some point later, XOF hired a PF to steal parasite research from the Diamond Dogs, with their eventually placing them in two storage containers for XOF to retrieve them.[14] However, Diamond Dogs ultimately retrieved the research materials before XOF could successfully extract them by chopper.

Kingdom of the Flies

The XOF were later redeployed into Central Africa after receiving reports that Sahelanthropus was in the possession of Eli, and his band of fellow child soldiers. Their mission was to eliminate Eli and his forces and to retrieve Sahelanthropus so that it could be under their control once more. Knowing the area was infested with the English strain parasite, the XOF wore hazmat suits to prevent themselves from getting infected.

During their search, many XOF soldiers fell victim to booby traps set by the child soldiers. After locating their target, an XOF marksman attempted to snipe Eli while he was in Sahelanthropus' cockpit, only for Tretij Rebenok to stop the marksman's bullet at the last minute, saving Eli. A full blown firefight ensued, with XOF pulling out after initially being overwhelmed by Sahelanthropus. When Diamond Dogs joined the battle against Eli's onslaught, the XOF began to hunt and gun down the other child soldiers, to ensure there were no witnesses. After Eli was defeated by Venom Snake, the remaining XOF forces moved in to eliminate him and retrieve the remains of Sahelanthropus, only to be gunned down by Snake.

Former members

Unit functions

Before 1970, XOF's primary function was to covertly support all FOX operatives to ensure that they completed their missions. This included providing field intel and even cleaning up any substantial messes that FOX had caused in order to eliminate all traces that FOX was there. During missions, XOF operatives were not allowed to directly intervene with FOX missions, being ordered to observe from afar and keep track of an operative's mission status. During Operation Snake Eater, Skull Face had been ordered by Zero to provide covert support for Naked Snake, but under no circumstances was he allowed to directly participate in the operation, needing the existence of the XOF to remain secret at all costs.

After FOX was disbanded, Skull Face and the rest of XOF were recruited by Major Zero to join Cipher, converted from a covert support unit into a elite strike force, specializing in a wide array of operations including assassinations, demolitions, and even genocide all while using complete discretion. According to a member of the Marine Corps at the United States Prison Facility in Cuba, they had special forces training and may have been heavy operators, with their being comparable to comic book characters.[18]

Utilizing their stealth training from when they were a support unit, one of XOF's top directives for operatives during missions was to leave absolutely no traces that they were ever there. An example of this was when the XOF were about to initiate their Trojan Horse operation on Mother Base, Skull Face had everyone including himself tear off their XOF patches from their uniforms and threw them out of the chopper to trick the MSF into believing that they were the UN inspection team, although their patches were later found by Big Boss while trying to rescue Chico and Paz. After learning of Big Boss's survival nine years later, Skull Face sent XOF soldiers, including the assassin Quiet, to assassinate the legend and to execute all the patients, staff, and anyone else present at the hospital, assuring utmost secrecy.

Since the unit's formation, all XOF personnel including soldiers, covert operatives, and even the Parasite Unit acted exclusively on Skull Face's orders. They followed every one of his commands without question, no matter how extreme or immoral, showing that they were extremely loyal to the disfigured commander. They would even go so far as to sexually torture victims when ordered by Skull Face if he couldn't get them to cooperate using violence, like when Skull Face ordered one of his men to rape Paz, a defenseless woman, in front of Chico, a mere child, after the latter refused to give him information on Mother Base.

While most of Zero's agents got their missions and orders via proxy, Skull Face was one of the few operatives who received his orders directly from Zero over a secure, untraceable phone line that was designed to keep Zero and Skull Face's conversations private, but was also designed to prevent Skull Face from pinpointing Zero's exact location from wherever he was calling as a precaution should Skull Face ever decide to betray him. While Skull Face did harbor an immense hatred for Zero, he accepted every mission Zero had given him without question, biding his time to strike while proving his allegiance.

Missions of higher priority went to the Parasite Unit, Skull Face's elite unit, which was composed of Parasite enhanced super soldiers known as the Skulls. The Skull's were assigned missions that required their unique abilities to ensure that the mission would not fail at any cost. The Mist Unit specialized in apprehending particular targets that could prove to be difficult to capture, using the mist as a smoke screen to hide their numbers and to confuse and wear out their enemies, making it easier to apprehend them. The Camouflage Unit specialized in marksmanship and reconnaissance, using modified Sinful Butterfly sniper rifles to pick off their prey with flawless accuracy and efficiency. Skull Face had this unit deployed to prevent Venom Snake from reaching Code Talker. Finally, the Armor Unit specialized in heavy assaults, using giant rocks and metal skin to overwhelm their opponent while taking minimum damage, making them extremely difficult to kill.


During the events of 1975 and 1984, typical XOF soldiers wore:

Mgs25th shot09.jpg
  • Grey drab flight suits.
  • Olive drab combat boots.
  • Chest harness.
  • SPIE harness.
  • Ammo pouches
  • Butt packs.
  • Balaclava.
  • Combat vehicle crewman's helmet with a designation number painted on.
  • Eye protection goggles.
  • CVC helmet liner with integrated headset.
  • Black brassard on the left arm with patches of their group's insignia, which they disposed of when about to infiltrate an area. The patches and logo for XOF is a color inversion of the FOX logo.
    Xof unit.png

They also wore white helmets with a blue stripe on them during the former. In the latter, they wore similar helmets, although some had a green stripe instead.

During the hospital raid of 1984, the XOF also wore yellow-tinted visor gas-masks, predominantly black body armor, and oxygen tanks.

XOF was known to use the following equipment between 1975 and 1984:

Firearms and Launchers

  • AM D114 Pistol
  • AM Rifle Type 69 AAS (Ground Zeroes Incident only)
  • Sz.-336 SMG
  • ALM 48
  • GROM-11

Thrown Weapons

  • Hand grenade
  • Smoke grenade
  • Stun grenade


Metal Gear Sahelanthropus.

In addition, upon taking OKB-Zero, XOF commandeered the following equipment from the Soviets for their use:

XOF also possessed a Metal Gear called Sahelanthropus (originally developed for the Soviets), which was located in Afghanistan.

Behind the scenes

Phantom pain trailer detail.gif

XOF first appeared in the PAX Prime 2012 demo for Metal Gear Solid V: Ground Zeroes (at the time simply titled as Metal Gear Solid: Ground Zeroes). In both the VGA 2012 trailer for The Phantom Pain, and the GDC 2013 trailer for Metal Gear Solid V: The Phantom Pain, there were soldiers shown attacking a hospital that utilize similar uniforms and equipment to XOF, although it was unclear at that time if they are the same group. The game confirms they are indeed XOF soldiers.

In the demo shown at the Kojima Productions Los Angeles studio live opening, the XOF members, when disposing of their XOF badges, also released a FOX badge, with the player later finding it after interrogating a soldier about it. It was later confirmed that the XOF patches were indeed collectible in-game, and that collecting them all will unlock the extra op missions "Déjà Vu" and "Jamais Vu." In Jamais Vu, Raiden is offered payment in the form of XOF patches in exchange for having him wipe out the Body-Snatchers that took over the Cuban base, implying that XOF had been wiped out in this storyline.

Collecting the XOF badges was referenced on the 12 Days of Metal Gear promotional event on the official Metal Gear Solid Facebook page leading up to the release of Ground Zeroes on Steam, acting as the equivalent of the lyric of "9 Ladies Dancing" from the namesake song "The Twelve Days of Christmas."

If the player equips the MSF Sneaking Suit in The Phantom Pain, one may see an XOF badge near Snake's pack. It's in the same location of the one that the player has to roll around to get.

At one point, Ocelot refers to them as "Kisses and Hugs, followed by a big F you" in reference to the letters making up the name.[note 1]

Despite XOF being the most influential antagonists in the game, their foot-soldiers only appear in gameplay during Mission 0 Awakening (as well as the companion Mission 46) and Mission 30 Skull Face. Gameplay-wise, the XOF are virtually identical to the game's other enemies, such as the CFA and Soviet soldiers, the only difference being they are all equipped with helmets; during Missions 0 and 46, these helmets provide no protection against headshots, but in Mission 30 they do deflect bullets. If OKB Zero is on high alert, will send another squad of soldiers in via the gunship overwatching the facility.

XOF's members speak English in American accents. As a result they reuse the same voice clips previously used for the Marines in Metal Gear Solid V: Ground Zeroes. This is also true for FOB Guards and CP and Mosquito's Assault Team and CP in Mission 22.



  1. ^ "Kisses and Hugs" is a reference to the letters X and O, respectively, due to the letters meaning "kisses" (X) and "hugs" (O). "Followed by a big F you" is a reference to the "F" portion of the name, as "F you" is obviously an abbreviated version of the vulgar phrase "Fuck you."


  1. ^ Metal Gear Solid V: The Phantom Pain , Kojima Productions (2015).
    Ocelot: No doubt about it. XOF... Cipher's covert strike force. Now they're taking orders from Skull Face.
  2. ^ Metal Gear Solid: Ground Zeroes demo, Kojima Productions (2012).
    Kazuhira Miller: Our 'friends' at Cipher suspect Paz could be a double agent. She’s being held for interrogation at a camp on the southern tip of Cuba.
  3. ^ Metal Gear Solid V: Ground Zeroes, Kojima Productions (2014).
    Marine: Those XOF guys... always hang around the admin building.
  4. ^ Metal Gear Solid V: Ground Zeroes, Kojima Productions (2014).
    Marine 1: When those choppers left, did you see them drop some stuff? // Marine 2: Yeah, looked like a bunch of leaves or something. // Marine 1: Right. // Marine 2: Yeah, I saw at least one of 'em land by the windsock.
  5. ^ Metal Gear Solid V: Ground Zeroes, Kojima Productions (2014).
    Marine 1: All quiet? Those new guys - you see their choppers? Who are they with? // Marine 2: Beats me, man. Green Berets... SEALs? // Marine 1: Those ain't no jarhead birds. I can tell you that. Some kind of paramilitary setup? // Marine 2: Well, some of the guys were saying... You know what? Best we just drop this, all right? // Marine 1: Uh, sure.
  6. ^ Metal Gear Solid V: Ground Zeroes, Kojima Productions (2014).
    Marine 1: All quiet? You know those choppers? I saw the marking on the side - "XOF." // Marine 2: "XOF"? That some kind of unit name? // Marine 2: Hell if I know. Maybe I saw it wrong. Any way, they're gone now. Guess we'll never find out.
  7. ^ Metal Gear Solid V: Ground Zeroes, Kojima Productions (2014).
    Marine 1: All quiet? I didn't get a good look, but their boss's face, man... // Marine 2: Yeah, you didn't need to get close to see that was no mask, either. // Marine 1: I tell you, I am glad they're outta here. It was like rubbing shoulders with dead men. // Marine 2: Yeah... Their boss, his crew... like phantoms, every last one.
  8. ^ Metal Gear Solid V: Ground Zeroes, Kojima Productions (2014).
    Marine 1: (Hey.) You hear about the special shifts guys have been pulling at the old prison area the past two weeks? // Marine 2: Yeah, some "high-value prisoners" or something. You get that duty and kiss your break time goodbye, man. My buddy was crying on my shoulder about it. // Marine 1 But that place has been dead for years. Now we got these I-don't-know-who's bringing in "enemy combatants" from stateside. // Marine 2: Right. And the CO is tearing his hair out. // Marine 1: Feel like I'm livin' in a prison, man.
  9. ^ Metal Gear Solid V: Ground Zeroes, Kojima Productions (2014).
    Marine 1: All quiet? What was that crew up to going back and forth between admin and the old prison area all the time? // Marine 2: (Yeah) One of the guys on gate duty was saying the same thing. They kept taking a prisoner with 'em... // Marine 1: And then they'd go down into the boiler room. // Marine 2: The area was off-limits while they did their questioning. Or "interrogation." // Marine 1: My buddy said he heard screams coming out... and music. // Marine 2: Music? That's some creepy shit.
  10. ^ Metal Gear Solid V: Ground Zeroes, Kojima Productions (2014).
    Marine 1: All quiet? They said to stay away from part of admin for now, right? // Marine 2: The boiler room. // Marine 1: Right. I hear they were doing some kind of questioning in there. // Marine 2: Questioning? // Marine 1: That "enemy combatant" in the prison area got taken down there every day.
  11. ^ Metal Gear Solid V: Ground Zeroes, Kojima Productions (2014).
    Marine 1: (Hey) You see that costume party those guys saluted to? // Marine 2: Yeah... Trench coat, and a ten gallon hat, and to top it off, that piece he's carrying is a sawed off old lever-action. Their CO's got style... for a bad guy in a western. // Marine 1: Nah man, he's just a Republican. // Marine 2: (And) Either way, he didn't look like no soldier to me. // Marine 1: And his bodyguards are all special forces ball-busting heavy operators. Last time I saw that, I was reading a comic book. // Marine 2: (Clicks tongue) I'm gonna have nightmares about this shit.
  12. ^ Metal Gear Solid V: Ground Zeroes, Kojima Productions (2014).
    Marine 1: (Yo!) I'm soaked to the bone. // Marine 2: Forecast says we got this until morning. // Marine 1: Looks like they're right - for once. Can you believe that crew taking their choppers out in this storm? It's pitch-black too. I knew they were crazy. // Marine 2: Either that, or they got some stone-cold rotorheads at the control. And they flew a tight formation - I guess they got a lot of trust. // Marine 1: Trust, my ass. You'd have to drag me onto one of those. // Marine 2: Yeah, no shit.
  13. ^ Metal Gear Solid V: The Phantom Pain, Kojima Productions (2015).
    Kazuhira Miller (To Know Too Much debriefing): Those men hunting for the target were Soviet troops who were colluding with the XOF. After securing the north observation post and learning the target's location, XOF sent assassins to eliminate him. Skull Face had turned XOF into his personal army, but the organization continues to exist even after his death. According to the man you extracted, their orders came through the same channel as always But is Zero really able to give orders in his current state? Or is somebody else calling the shots for XOF? For Cipher? What the hell... ?
  14. ^ Metal Gear Solid V: The Phantom Pain, Kojima Productions (2015).
    Kazuhira Miller: Boss, research materials have been stolen from Code Talker's mansion. The materials were packed into two containers and hidden in the jungle southwest of the mansion. You have to recover those containers. The pick-up crew coming for those documents is none other than XOF. That's right - they're still active even after Skull Face's death. Now that he's no longer in charge, their original chain of command has been restored. Meaning if XOF gets those documents, Code Talker's research ends up in Cipher's hands. According to Code Talker, the research papers account for over 50 years of study. The problem is the vocal cord parasites. If the papers documenting that research fall into Cipher's hands, they'll take another long, hard look at them. The "ethnic cleaners" we thought were history will become a reality. America - Zero - will have a weapon far more powerful than any nuke. Even worse, if this knowledge were to leak... The world - humanity - can't be entrusted with this kind of power! Recover the containers before the enemy extraction choppers arrive.
  15. ^ Metal Gear Solid V: The Phantom Pain , Kojima Productions (2015).
    Ocelot: That's an XOF soldier. Previously, XOF was made up mostly of American Vietnam vets, but these days they headhunt from Special Forces units all over the world.
  16. ^ Metal Gear Solid V: The Phantom Pain , Kojima Productions (2015).
    Ocelot: That's an XOF soldier. Previously, XOF was made up mostly of American Vietnam vets, but these days they headhunt from Special Forces units all over the world.
  17. ^ Ocelot mentioned that by the 1980s, XOF headhunted from Special Forces units all over the world, which was further supported by extracting several XOF soldiers in Mission 30: Skull Face, where it reveals many of their languages were of various Eastern European dialects.
  18. ^ Marine 1: (Hey) You see that costume party those guys saluted to? // Marine 2: Yeah... Trench coat, and a ten gallon hat, and to top it off, that piece he's carrying is a sawed off old lever-action // Marine 1: Their CO's got style... for a bad guy in a western. // Marine 2: Nah man, he's just a Republican. // Marine 1: (And) Either way, he didn't look like no soldier to me. // Marine 2: And his bodyguards are all special forces ball-busting heavy operators. Last time I saw that, I was reading a comic book. // Marine 1: (Clicks tongue) I'm gonna have nightmares about this shit.
  19. ^ This is implied in the mission failed cutscene for "Traitor's Caravan" if the player fails to extract the truck before it reaches its destination.

MGSV Ground Zeroes XOF Badge Playthrough-0

MGSV Ground Zeroes XOF Badge Playthrough