The Virginia opossum (Didelphis virginiana), also known as the North American opossum, is the only opossum living north of Mexico, its range extending south into Central America. It is the northernmost marsupial in the world. In the United States and Canada, it is typically called a possum, 'possum or opossum. It is a solitary nocturnal animal about the size of a domestic cat, and a successful opportunist.