Metal Gear Solid - Metal Gear REX

Metal Gear is the name for a series of mecha in the Metal Gear game series. Metal Gear REX is a Metal Gear model that appears in the game Metal Gear Solid designed by Yoji Shinkawa. Unlike previous Metal Gears, its legs are heavily armoured and reinforced.

Metal Gear REX has near-impenetrable compound armour, a pair of 30 mm Gatling guns, anti-tank missiles, and a free-electron laser, to protect itself from conventional forces. Its primary weapon, however, is a magnetic railgun capable of delivering an untraceable nuclear warhead anywhere in the world, without the propellant trail or launch flare that gives away the launch position of a traditional ballistic missile. 

1. Mecha - The term mecha may refer to both scientific ideas and science fiction genres that center on giant robots or machines controlled by people. Mechas are typically depicted as humanoid mobile robots.