Cut Halo 4 vehicles
From Halopedia, the Halo wiki
With the release of Halo 4 on PC as part of the Master Chief Collection, the Falcon model was added to the game's files and can be spawned via modding. The Falcon model in question is not a useable vehicle, but instead a lower-resolution model intended for background usage. As such, it has a low polycount and texture size, and no collision or gameplay useability.
Early Mantis iterations
When initially conceived, the Mantis was heavily inspired by the Mark I ADS from the Halo Legends short, Prototype. This armoured exoskeleton was initially concieved to fit numerous roles, mechanics and shapes alongside featuring a dedicated shield. This early Mantis also had the ability to use a jetpack, thrusters and a railgun, and an early prototype was developed which consisted of Master Chief riding inside and driving a larger Master Chief. This later evolved into a full mech, though remnants of this early idea could be seen in some concept art and early models which featured booster-like jets on the shoulders. These boosters can be viewed in-game, via the Mantis holograms on the Dominion vehicle spawn pads.
At some point in the game's development, an updated and redesigned iteration of the Type-48 Revenant, which first debuted in Halo: Reach, was intended for inclusion in the game. The vehicle was concepted by 343 Industries concept artist Glenn Israel and high-poly modelled and textured by hard surface artist Can Tuncer, and implemented in the Halo 4 tags build. The vehicle can be seen spawned on several cut maps including
The Revenant has seen a major redesign since its iteration in Reach, with the vehicle as a whole being generally bulkier and up-armoured compared to the original version. Instead of the driver controlling a light plasma mortar, the vehicle now has an automatic plasma turret in the back which can be manned by an independent gunner - making the vehicle more akin to the Spectre or Warthog.
With the release of Halo 4 on PC as part of the Master Chief Collection, the Revenant was added to the game's files and can be spawned via modding.
The Type-47B Scarab from Halo: Reach remains in the files of Halo 4, and can be spawned in The Master Chief Collection via modding. The core can be destroyed, though the vehicle does not explode. In the regular edition of Halo 4, the Scarab is present in the files of the Spartan Ops map Harvester.
The Space Banshee is present in the files of Halo 4 in The Master Chief Collection and can be spawned in via modding. The vehicle is flyable, though remains untextured and is prone to glitching when performing Banshee tricks.