GEKKO or IRVING's are an Optical-Neuro AI controlled unmanned bipedal battle drone series. They are also known as "Unmanned Gears". They have many varieties in design including a variant called Suicide GEKKO, whose main form of attack is blowing up via a nuclear demolition charge, taking out all around it. They appear as common enemies in the video games; Metal Gear Solid 4: Guns of the Patriots, and Metal Gear Rising: Revengeance.