Grison (Galictis vittata), a carnivorous mammal, of the family Mustelidae, common in Central and South America and Mexico. It is about the size of a marten, and has the upper surface of a bluish-grey tint, and the under surface is dark brown. The grison lives on small mammals and birds, and in settled districts is destructive to poultry. Allamand’s grison (G. allamandi), with the same range, is somewhat larger. Another member of the genus is the tayra or taira (G. barbara), about as large as an otter, with a range from Mexico to Argentina. This species hunts in companies (see Carnivora).