The Duck Class Amphibious Unit. There is the attack varient and the harvesting varient. the attack varient is tougher and has a gun but tips over easily. The harvester varient cannot take very many hits and is unarmed but is a cheap and early-game alternative to the harvester MKII. it is also harder to tip over. both units can move well over water AND land. they are also cheap and easy to build so you can mass-produce these things. it is recommened to bring a unit with a magnet to attacks because, once again, sudden movements on rough terrain or cannon shots can flip an attacking duck