Opossum

Opossums are North America's only marsupial, turning up in habitats as different as forest, farmland, and suburban neighborhoods. Grayish-white fur, a naked prehensile tail, and a pointed, pink-nosed face make them unmistakable among North American mammals. The famous "playing possum" act is actually involuntary — a catatonic response to extreme threat rather than a deliberate performance — and opossums carry another odd advantage too, an unusual resistance to certain diseases and toxins, including some snake venoms.