Clown killifish (Epiplatys annulatus) are a small fish that only lives for about 1 year. They do best in a single species tank or tanks with small slow moving fishes (pygmy Corydoras, Khuli Loaches, etc).
They are sexually mature when 3 months old and lay small batches of eggs each day. If the adults are well fed the babies can be kept in the same tank as the parents. You can keep them in pairs (1 male & 1 female), or in groups with several males and females.
The aquarium should be at least 18 inches long and contain an air operated sponge filter, heater and lots of plants. Have the temperature on 20-30C, ideally around 24-26C.