guns and missile launchers akin to REX. A third variant is the special purpose Suicide Gekko, designed to invade enemy facilities in groups before self-destructing en masse. Similar in combat terms when compared with traditional Metal Gear models, relatively little firepower is needed to actually destroy one. A quick blast with an assault rifle may cause one to trip if shot in the legs. Corresponding shots to the "neck" can destroy a Gekko with small arms such as a M4 carbine or FN P90. However, when a Gekko falls, it can quickly regain its footing even if tripped onto its head. Nonetheless, a heavy weapon such as any rocket-launcher, an M82A2, or the Rail Gun, can be used against the Gekko without requiring it to be collapsed. The Gekko makes use of sound in psychological warfare, particularly animal noises (such as cicadas while on the prowl to create an atmosphere of unease, and bull sounds in direct combat as a means of unnerving the enemy). They feature characteristics that are biomechanoid to some degree, as they have been shown to "bleed" when sliced at the legs as the machine could use a blood-like self-repairing nanopaste like RAY, though severe wounds on seemingly mechanical components have been known to "bleed" as well. In addition, they expel a green liquid, which may be lactic acid produced by the artificial muscles. Director Hideo Kojima stated in a pre-release interview that the Gekko are not the game's titular Metal Gears, stating that they are more like a jeep or a tank compared to the conventional Metal Gears such as REX and RAY. The Gekkos reappeared in Metal Gear Rising: Revengeance. Arms of Dwarf Gekkos are attached to Desperado operative Mistral while the Metal Gear EXCELSUS has Gekko escorts called Gekko UG. Metal Gear Mk. II and Metal Gear Mk. III The Metal Gear Mk. II is a robotic companion to Old Snake in Metal Gear Solid 4. This unit is similar (albeit a bit more angular in appearance using an OLED screen and has wheels instead of feet) to the Snatcher version and is controlled by Otacon. This version is not meant to be a weapon, instead he uses it to provide ammunition and advice to Snake in the Middle East, South America and Eastern Europe. The Mk. II can also be used as a recon device, turn invisible, and shock enemies knocking them