water opossum

The water opossum (Chironectes minimus), also locally known as the yapok (/ˈjæpɒk/), is a marsupial of the family Didelphidae. It is the only monotypic species of its genus, Chironectes. This semiaquatic creature is found in and near freshwater streams and lakes from Mexico through Central and South America to Argentina and is the most aquatic living marsupial (the lutrine opossum also has semiaquatic habits). It is also the only extant marsupial species in which both sexes have a pouch. The now extinct thylacine, commonly referred to as the Tasmanian tiger, also exhibited this trait.

The local name for the water opossum, "yapok", may come from the name of the Oyapock River in French Guiana.