This transformable A-class HM was designed based on the Dizard. Poseidal developed the basic design, and Poseidal military engineer Mesh Maker developed it in the Tridetoal Regular Army's Dova Airport factory. Its codename is "Stack." It's the first A-class HM newly designed on the Pentagon World in hundreds of years. It combines Poseidal and Yaman technologies, and is an ambitious machine that incorporates a transformation feature not found in previous HMs. However, it lacks the Spiral Flow System, so it can hardly be said to have achieved its objectives. Its first battle was headlined by Gabret Gabree, but poor operation (attempting to walk with its legs folded) prevented it from performing its full potential, leading to its harsh criticism that "a weapon must reliably perform a single function." It was eventually seized by Daba and his group, who infiltrated the ship. Their modifications (refurbishments) transformed it into the L-Gaim Mk-II (described below), achieving its original goal of "technology fusion."

For high-speed travel, it transforms into a flying form known as the Prowler (Land Booster).