C. niger

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
 * Chelonoidis niger, The Galápagos tortoise or Galápagos giant tortoise (Chelonoidis niger) is a species of very large tortoise in the genus Chelonoidis
 * 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.