Water opossum

The water opossum ("Chironectes minimus") is also known as the yapok. It is an aquatic marsupial and a member of the opossum family. It has black and grey waterproof fur and webbed hind feet. It is "the only living marsupial where both sexes have a backward-pointing pouch". 
The animal is found in the freshwater streams and lakes in Mexico, Central and South America. The water opossum lives in bankside burrows. It comes out after dusk to search for fish, crustaceans and other aquatic animals, which it eats on the bank.
The yapok's webbed back feet helps it chase its prey in the water.