Phylum: Chordata Class: Mammalia Order: Carnivora Family: Mustelidae Subfamily: Lutrinae Genera: Amblonyx Aonyx Enhydra Lontra Lutra Lutrogale Pteronura Otters are amphibious (or in one case aquatic ) carnivorous mammals . The otter subfamily Lutrinae forms part of the family Mustelidae , which also includes weasels , polecats , badgers , as