A heart-warming picture book about a green hippo who struggles with being different and the friends who help him accept his individuality, by award-winning author-illustrator Petr Horácek.Green Hippo is feeling sad. Why? Because someone said green hippos don't exist! Frog, Elephant and Giraffe try to cheer him up, but Green Hippo is feeling too down to listen. But maybe Green Hippo will make a discovery of his own as he goes down to the river and sees the beautiful colours of the world all around him...