The marsh mongoose or water mongoose (Atilax paludinosus) is a medium-sized mammal, but a large mongoose. Its weight can range from 2 to 5.5 kg (4.4 to 12.1 lb), with an average range of 2.5 to 4.1 kg (5.5 to 9.0 lb). From the head to the base of the tail, these animals range from 44 to 62 cm (17 to 24 in), with the tail adding 25–36 cm (9.8–14.2 in). It is a member of the mongoose family and the only member of its genus.