Moomintroll is cheerful and chubby and lives in the magical Moominvalley with his mother, Moominmamma, his father, Moominpappa and all of their friends. Throughout the winter, the Moomins hibernate, but before they go to sleep they fill their tummies full of pine needles. In spring they wake up, ready for their fun-filled summer adventures. This is the story in which Moomintroll finds a big hat - a magical Hobgoblin hat, no less . . .