Aquatic mammals are a diverse group of animals that live in the water. The term includes the ORCA (4 letters), a large toothed WHALE; the otter (5 letters), a semi-aquatic mammal with webbed feet; the SEAL (4 letters), a carnivorous marine mammal; the manatee (7 letters), a large aquatic mammal; the HIPPO (5 letters), an amphibious mammal; the PORPOISE (8 letters), a small toothed WHALE; the DUGONG (6 letters), a large aquatic mammal; the WHALE (5 letters), a large aquatic mammal; the muskrat (7 letters), a semi-aquatic rodent; the OTARY (5 letters), a sea lion; the sealion (7 letters), a large sea lion; the hairseal (8 letters), a species of SEAL; and the shipscat (8 letters), a species of SEAL.