First, as "Gypsy Rockstar" pointed out:
Castorocauda lutrasimilis, Latin for beaver tail and similarity to the otter, was recently discovered by scientists in China. It is a cross between the beaver, otter, and platypus (but related to none). It also predates the first know water mammal by only 100 million years. Here is the only photo they have been able to find of it (although I am suspect because I am pretty sure its extinction predates underwater cameras).
Then, today, "Because" gave me the heads up on another unique water creature:
Divers have discovered a new crustacean in the South Pacific which resembles a lobster and is covered with what looks like silky, blonde fur, French researchers say.
Scientists said the animal, which they named Kiwa hirsuta, was so distinct from other species that they created a new family and genus for it.
Giant Beavers and Albino Furry Lobster... what will they think of next? Stay tuned!