a series of explosions. Sahelanthropus is also armed with a prototype railgun that can only be fired from its crouched position, and an array of machine guns and missile launchers. It can also release unmanned drones that scan the area for targets. Unlike other Metal Gears, Sahelanthropus cannot fire a nuclear weapon; rather, its body is made up of depleted uranium which can be enriched to become uranium-235 by the metallic archaea to 90% purity. Given Sahelanthropus' size, this creates a bomb with an extremely high yield. Lead engineer Emmerich described the choice of depleted uranium as being a direct result of the need to keep the weapon's mass to a minimum despite ceramic armor offering better protection. Within the game, Sahelanthropus is unfinished, with Emmerich unable to complete the control unit as he wanted to protect Peace Walker's vulnerable AI pods by encasing the pod used to regulate the systems within the armor. However, the weapon is controlled by the psychic Tretij Rebenok to give additional mobility for Skull Face. It is transported to Diamond Dogs' Mother Base to act as a symbol of their history. Sahelanthropus is later stolen by Eli with aid from Tretij Rebenok. Models in other games These models are not part of the mainstream Metal Gear series continuity, either because they appear in a non-canonical game (Snake's Revenge, Metal Gear: Ghost Babel and Metal Gear Acid) or because the game in which they appear is not a Metal Gear game at all (Snatcher). Metal Gear Mk. II (Snatcher) The Metal Gear Mk. II in Snatcher is the robotic sidekick of the game's protagonist, Gillian Seed, a JUNKER agent. He is a navigator built by JUNKER engineer Harry Benson to assist Gillian and facilitate his investigation. According to Harry, he was designed after the "Metal Gear menace from the 20th century." He is equipped with a forensic analyzer, as well as a videophone Gillian uses to communicate with his wife and other characters. The Metal Gear is voiced by Mami Koyama in the Japanese versions and by Lucy Childs in the English-language Sega CD version. A hand-size model appears in the spinoff SD Snatcher named Petit Metal, its function in the game is to display statistical data during battle or to automatic battle for the player. Metal Gear 2 The Metal Gear 2 from Snake's Revenge is a successor to the original Metal Gear described