ZOOO is an entertainment application for HoloLens, with which you can summon life size animals wherever you are. With this app you can summon large life size animals which you don't usually have the chance to see in real life and examine them up close. If you choose a giraffe, it will appear and its head will go through the ceiling if you are indoors. If you choose an elephant, it will appear. However, due to its immense size, the floor may break under its weight and it will fall through the floor. This app can show you the huge size gap between these big animals and humans by utilizing the unique technology of HoloLens, and it will let you learn about them in a fun way. In addition to currently living animals, you can also bring back extinct animals such as dinosaurs, which will make your experience in this app even more unprecedented and extraordinary.