Anax tristis (Hagen, 1867), the Black Emperor, or Magnificent Emperor, is the largest African dragonfly, also one of the largest worldwide dragonflies. It has a max size of 120 mm, wingspan up to 135 mm. It has green eyes and thorax, black abdomen with yellow spots. Males have a longer abdomen than females. Flight season from November to March.

It is found in Angola, Botswana, Cameroon, Chad, Comoros, Ivory Coast, Equatorial Guinea, Gabon, Gambia, Ghana, Guinea, Kenya, Liberia, Madagascar, Malawi, Mauritania, Mozambique, Namibia, Nigeria, South Africa, Sudan, Tanzania, Togo, Uganda, Zambia, Zimbabwe, possibly Burundi, and possibly Ethiopia. Its natural habitats are subtropical or tropical dry forests, subtropical or tropical moist lowland forests, dry savanna, moist savanna, subtropical or tropical dry shrubland, subtropical or tropical moist shrubland, swamps, intermittent freshwater lakes, freshwater marshes, and intermittent freshwater marshes.

The species is common and widespread in the tropical parts of all southern African countries. There are no records from the southern parts of South Africa, Namibia and Botswana. There is a single record from western Cape, but it is likely to belong to a vagrant specimen. This is a widespread species with no known major widespread threats and that is unlikely to be declining fast enough to qualify for listing in a threatened category, therefore it is assessed by IUCN Red List as Least Concern.