Mark Rober, the former NASA engineer who built the world's largest Nerf gun is back with another biggie and it is certified by the Guinness Book of World Records as the World's Largest Soaker. Got something bigger to bring to a water fight than this? Watch the video... "Introducing the Guinness World Record Largest Super Soaker evaa at 7 ft long!! This could definitely shoot Ralphie's eye out."