The Moomins are a family of characters created by Finnish author Tove Jansson. They are large, round, and friendly creatures resembling hippos, living in a peaceful valley called Moominvalley. The stories revolve around their adventures and interactions with various other characters, including Snufkin, Little My, and Hattifatteners. The Moomin stories explore themes of friendship, nature, and the importance of family. They have been adapted into various forms of media, including animated series, films, and stage plays, gaining popularity worldwide. The whimsical illustrations and gentle storytelling make them beloved by both children and adults.