Lovingly dubbed the “mothergoose” by frontline infantry men and women due to its increased size over the M274, this particular variant shown is Liang Dortmund's heavy-duty modification of the standard M290 ATV. The result is a nimble but rugged Mongoose with extra armor.
The M290 All-Terrain Vehicle, also known as the Mongoose, is a UNSC light ground reconnaissance vehicle, introduced in the post-war era as a replacement to the outdated M274 Mongoose. It goes by the colloquial names of 'Mongoose' or 'Mothergoose'. In addition to the standard variant, a variant with twin mounted driver-controlled grenade launchers exists, called the Gungoose.