Yapok
The yapok is the world’s only marsupial that hunts in the water. It is a diurnal animal that hunts in a way similar to a raccoon. It dives down to the bottom of a river or other water source with its eyes closed, and feels around for fish and insects. Yapoks look very similar to large rats, even though they are not a part of the rodent family. These incredible critters are in grave danger of extinction.
(an artist's rendition of the yapok)