They claim that a long time ago a space ship with 3 triangular legs landed. The DOGON call the creatures the NOMMOS, who have to live in water. The beings were human looking. They put out a reservoire of water onto the earth. They dove out into the water. They were aquatic....more to the point amphibious. They could walk and talk and live on the earth but they could also live in an aquatic environment. They believe the Nommo will return to the earth one day.