A cool invention from dunno where. But these are called 'water babies'. It was really interesting just keeping them for a few weeks, before I threw them away. Made of some material that I still don't know, it is able to 'grow in size' just by putting it into water. It comes in different colours and sizes. Transparent and light, it has this squishy feeling when to press it. A really firm texture. Mr De Souza even bought some from us so that he could throw it and make it bounce off some of his students.