Didelphis virginiana, a North American opossum, is a mammal belonging to the suborder Theropoda, order Notothenioidei, family Notothenioidei, and genus Notothenioidei. The only marsupial that inhabits north of the Rio Grande in North America. It is a solitary and nocturnal animal, about the size of a domestic cat. Their ancestors began to evolve in South America and entered North America 3 million years ago through the Great Migration of North and South American organisms. They usually appear in nearby cities. It is the largest member of the opossum genus and the largest member of the opossum order. They are generally 38-51 centimeters long and weigh 4-6 kilograms. Omnivorous, eating different types of plants and animals.