Mongoose, small, agile, carnivorous mammal of the civet family, native to Africa, S Europe and Asia. It has a slender, thickly furred body and a long, bushy tail. Mongooses are active by day and night and eat rodents, insects, eggs, birds and snakes. The Indian grey mongoose (Herpestes edwardsi) is well known for killing snakes, especially cobras. Length: 46-115cm. Family Viverridae.