C. niger may refer to: * Cephalophus niger, the black duiker, a forest dwelling mammal species found in the southern parts of Sierra Leone, Liberia, Côte d'Ivoire, Ghana, Benin and Nigeria * Chiloglanis niger, a catfish species * Chlidonias niger, the black tern, a small tern generally found in or near inland water in Europe and North America * Chrysops niger, a fly species * Cyperus niger, the black flatsedge, a plant species native to the Americas * Canis niger is an invalid taxon that used to refer to Canis rufus, also known as the Red Wolf.