From Halopedia, the Halo wiki
"Scout" Warthog vehicles could be considered the "default" state of Warthogs, with their primary difference from other variants being their lack of any discernible armament. Removing the primary weapon from the M12 FAV is typically a simple and straightforward operation, allowing for weapons to be removed as seen fit and the bed of the vehicle used for cargo and/ or personnel transportation. When used to transport personnel, a Scout Warthog is capable of supporting at least five people.[Note 1]
Flatbed Warthogs are typically employed by the UNSC for scouting purposes, transportation of food and fuel and as light transports when necessary. Sometimes, some Warthogs are de-armed due to critical resource shortages. The Office of Naval Intelligence also makes use of Scout Warthogs, though they bear only superficial similarities to their regular counterparts.
De-militarised Warthogs are also sold to private corporations such as the Liang-Dortmund Corporation alongside other milspec hardware. Similar vehicles with no weapons are also sold on the civilian market, such as the Hog and M12S Warthog CST. Some de-armed Warthogs are utilised for racing.
In 2525, the Colonial Militia on Harvest had at least two Warthogs used as flatbeds. They would later see use in the Harvest campaign, Battle for Arcadia and Battle of the Etran Harborage in 2531 due to their carry and manufacture by the UNSC Spirit of Fire and its deployed Firebases. "Scout" Warthogs would see continued use throughout the Human-Covenant War in varied roles when needed, thanks to their versatility. In 2552, several flatbeds were present at UNSC Training Facility Bravo.
The upgrade to the M12B chassis in the late/ post-war era would also, by extension, create M12B Scout Warthogs. In 2558, the UNSC Infinity carried dearmed Warthogs in its hangars. Scout Warthogs were also employed on Meridian by the Liang-Dortmund Corporation.
In Halo 3, Flatbed Warthogs primarily appear on the map The Pit alongside several M831 Troop Transport Warthogs, outside of the playable area of the level. Both of the scout Warthogs on the map are slightly damaged. Regular Warthogs can be "converted" into flatbeds through the use of the turretless vehicle glitch.
In Halo Wars, all newly-created Warthogs spawn without any armament, making them unable to attack enemies except by way of splattering. The first Warthog upgrade available, however, arms the vehicles with an M41 Vulcan.
Turret-less Warthogs can be created in Halo: Reach through the use of the same glitch as can be used in Halo 3.
In the first episode of Halo: Infinity, a flatbed Warthog with two Marines riding in the back cargo bay can be seen briefly.
Halo 5: Guardians
Halo 5: Guardians introduces the Scout Warthog as a class of vehicle that can be seen in the campaign and called in during Warzone matches, via the Requisition system. Like the other UNSC vehicles in the game, the Scout Warthogs come in standard, Corp, Tundra, Woodland, Urban and ONI variants with successively stronger armour. In addition, the "Rally" Warthog introduced as the Rally Scout Warthog provides increased speed over other Warthog models. Most Scout Warthogs can be called in at REQ level 1, and are useful for rapid transportation around the large Warzone maps. The higher-tier Scout variants such as the ONI Scout are also useful in early rounds of Warzone Firefight for ramming infantry and scoring rapid kills on groups of low-level infantry.
List of appearances