Taxonomy. Common, or Eastern, king snakes are medium-sized snakes reaching three to six feet (.9 to 1.8 m) in length. Often called 'chain snakes' or 'chain kings' because of the white chain-like markings on their body, this snake is easily recognized.The snake is a shiny black with a criss-cross pattern of white or yellow lines.he eastern king snake range includes southern New Jersey to West Virginia, south to north Florida, and west to the Appalachians and southeastern Alabama. The eastern king snake is fed mice, rats, and chicks.