User blog comment:Mckrongs/Monster Hunter 4 for the Nintendo 3DS/@comment-184.38.5.102-20121230160044/@comment-184.38.5.102-20121230215214

So one new class confirmed,Amphibian, and another class that isn't confirmed yet ,Chelicera.To be honest,Chelicera is a reference to Chelicerae (mouth parts for arthropods like arachnids) and it could mean their renaming an old class like Carapaceons.