The Marines' fastest ground vehicle is the M274 ULTRA-LIGHT ALL-TERRAIN VEHICLE or 'Mongoose'. Essentially four wheels and an engine, this ATV can travel very fast over nearly all types of terrain.

Because it possesses no defensive or offensive capabilities whatsoever, Human troops have been known to seat weapons specialists on the rear seat to provide firepower during combat.

NOTE: The Mongoose was originally slated for inclusion in Halo 2, but didn't make the cut because none of the game's missions had a unique role for the vehicle to play. Anywhere it could be used, a Ghost or Warthog was deemed to be more suitable. Unlike the Warthog, it only seats two instead of three; unlike the Ghost, it can seat two instead of only one. Unlike both, it has no weapons of its own, the only Halo vehicle that is completely unarmed; even Pelicans have weapons, at least starting in Halo 2, even if they aren't usable by the player.

With a higher speed than a Warthog and an ability to carry two players, unlike a Ghost, one can easily imagine the utility of this vehicle in objective multiplayer games, as well as in cooperative campaign play.