Hatch your own dinosaur with the Ginormous Hatchin' Grow Dino. This large 4.5 inch dinosaur egg will grow into a full 12 inch dinosaur. place the egg into a container of cool water. (Make sure the egg is fully submerged). Allow it to stay there undisturbed for 48-72 hours. During this time, the dino will start to hatch and break out of its shell! Once the dino has fully broken out of the shell, replace the old water with new water and watch the dinosaur grow!