The Gama Goat was a six-wheel drive semi-amphibious off-road vehicle originally developed for use by the US military in the Vietnam War. The Goat uses an articulated chassis, so that from distance it appears to be a four-wheel drive vehicle pulling a two-wheel trailer, but it is a single six-wheel vehicle with a four-wheel steering arrangement with the front and rear wheels turning in opposite directions. It was famous for its ability to travel over exceptionally rough and muddy terrain.