This mech paper model is Rampage, a BattleMech produced by the Rim Worlds Republic, from the game Classic BattleTech, the papercraft is created by Yogsolthan. The size of finished model is about 233 (H) x 170 (W) x 144 (D) mm.
The 'Mech was originally built and used as a standard line unit, but it was upgraded to a fast assault 'Mech in 2767, following Stefan Amaris' successful coup that installed him as the nominal leader of the Terran Hegemony. With the occupation of Star League R&D facilities, his Periphery nation was finally able to produce the SLDF's advanced weaponry.
The Rampage's upgrade utilized Endo Steel and an XL Engine to save weight. As engineers debated the best way to make the Rampage faster, they settled on installing the new MASC system, which accelerates the 85-ton 'Mech to 86 km/h in bursts. While its speed gives it a measure of protection, the design also sports a massive sixteen tons of PanzerSlab 9 armor. [Source: sarna]
You can download the papercraft model here: Classic BattleTech - Rampage Free BattleMech Paper Model Download