Yersinia pestis (also known as the Plague, Sylvatic Plague, and the Black Death) is a Gram-negative coccobacillus and zoonotic bacterium found in small mammals and their fleas. Y. pestis forms small (1-2 mm), grey-white to yellow, “hammered copper” colony formations when cultured. Plague manifests in symptomatic hosts in bubonic, pneumonic, or septicaemic forms, determined by the route of infection. It is 1 of 6 original communicable diseases that are reportable to the World Health Organisation by member states.