When dry, these six little dinosaurs will all fit easily in the palm of your hand...but when placed in water, they'll absorb many times their own weight in water. Made of a superabsorbent polymer, our green Gro-Beast Dinosaurs start at about 1 inch long and grow to over 4 inches each! Each package contains six different types of dinosaur. A wonderful way to work on variables, measurements, mass, volume, and more. Dinosaurs will shrink back to their original size as they dehydrate. We recommend using distilled water for best results, but why not try submerging a few in other liquids to see how their growth changes?