DejaVuPortableOps Cropped2 "Hmm, I don't remember that one. It mustn't be that important."
This article is about a subject from outside Hideo Kojima's core "Metal Gear Saga." It has some level of canonicity within the continuity, but reader discretion is advised.[?]


Mastiff was a type of Unmanned Gear deployed in 2018. Humanoid in nature, it was hulking and had its hands hidden in armor, with MK19 Automatic Grenade Launcher turrets on its wrists. They were also capable of pummeling an enemy into the ground, putting an enemy into a single arm stranglehold, and, if all else failed, doing a dropkick with both feet to knock the enemy back. They were designed to replace infantry in next-generation wars.


World Marshal Incidents

See also: Raid at World Marshal, Ambush in Africa, Abkhazian Coup, Investigation in Guadalajara, Raid in Denver, and Operation Tecumseh

In 2016, Samuel Rodrigues, during his raid at the HQ building for World Marshal, encountered several Mastiffs during this time.

In 2018, several Mastiffs were assigned to Abkhazia to aid in the Abkhazian Coup. However, thanks to Mistral's machinations against fellow Desperado ally Khamsin, the Mastiffs were all destroyed by the then-AWOL LQ-84i, which ironically led to Maverick's mission against Desperado being made a lot easier.

Raiden, as a Maverick agent, managed to somehow find design specs relating to the Mastiff prior to his failed mission in Africa. Maverick later retrieved his arm and located two blueprints of the Mastiff, the latter of which detailed its head and was stumbled upon while Maverick was recovering data relating to Raiden's time at Force XXI, although they required passwords to get to the encrypted files, and the blueprints themselves ended up corrupted, due to the damage to Raiden's arm. Desperado utilized Mastiffs during battle. Raiden, during a mission in Mexico to locate a research facility, ended up being ambushed by a Mastiff in the sewers, although he quickly destroyed it to prevent it from alerting Desperado. Several more Mastiffs were also nearby patrolling the sewers, which Raiden ambushed/evaded via the catwalks above. The Mastiff's presence, alongside the Dwarf Gekko and Vodomjerka UGs, were to collect combat data for use in VR simulations for UG development, and not for actual guard duty, contrary to what Maverick initially thought.

Several Mastiffs later patrolled an abandoned Denver rail line dating back to the 1800s, in anticipation of Raiden's infiltration through the area. They also were deployed to defend the World Marshal HQ directly during this time, alongside to prevent Raiden's escape.

Their overall behavior, including their running movements and beating their chests in an aggressive stance, are similar to gorillas. It was largely because of this that they were considered for replacing common infantry at most, as they did not resemble humans in terms of behavior. 

Behind the scenes


The BB Corps concept artwork in Metal Gear Solid 4 that served as the basis for the Mastiff.

The Mastiff (マスチフ Masuchifu) first appeared in the E3 2010 trailer for Metal Gear Rising: Revengeance (when the game was known as Metal Gear Solid: Rising) as an enemy that Raiden ambushed and proceeded to cut up via zan-datsu, before absorbing its spinal cord energy and then crushing it (although it was not identified as such). It was based on designs made by Yoji Shinkawa that were originally intended for the Beauty and the Beast Unit.

The Mastiff was not given a name until after the "Make It Right: decryption" viral marketing site uploaded artwork of the Mastiff that required a command key code to access, with the in-universe explanation given on the Metal Gear Solid Facebook page being that Maverick located an encrypted file cluster that was password protected, and found clues to the password in the names "Anatolian", "Alpine", "Bully Kutta", "Cane Corso", "Bordeaux", "Pyrenean", and "Neapolitan", all of which are breeds of the mastiff dog breed.

The Mastiff's head has a striking similarity to the helmets used by the FROGS during the Guns of the Patriots Incident.

The blueprint file clusters being found on Raiden's left arm, along with similar data being found on thirty other cyborgs' left arms that were explicitly referred to as Patriot data with the latter, implies that the Mastiffs may have originally been a Patriot creation prior to their shutdown in 2014.

Destroying 10 Mastiffs in a playthrough will award the player with the achievement/trophy "Silverback", a reference to their gorilla-like nature.

Originally the Mastiff had a short-barrel Browning M2HB, but this is replaced with a custom Mk 19 grenade launcher in the final version.

In the Piggyback strategy guide, the normal Mastiff variant is identified as a Special Forces variant.

The Mastiff also appeared in the Versus Battle on the official series website.

"STRENGTHS: Brownings, Armor, Gorilla-Strong
WEAKNESSES: Big and Bulky
FEATURED FACT: If a Mastiff pummels you or even just grabs you, it can crush you with a single arm
-Mastiff description in Versus Battle.