In Dogon mythology, the amphibious ancestors called the Nommo are associated with and said to descend from Sirius.
The Nommo are central beings in Dogon cosmology, often described as water spirits, ancestral figures, twins, or fishlike androgynous creatures. In accounts recorded by French anthropologists Marcel Griaule and Germaine Dieterlen, they arrived in a celestial ark and helped establish order, language, ritual knowledge, and human society.
Sirius is the brightest star in Earth’s night sky and is part of a binary system with Sirius B, a white dwarf. Popular retellings often say that the Dogon possessed detailed knowledge of Sirius B long before modern astronomy, but that claim is heavily disputed. Anthropologist Walter van Beek reported that Dogon informants did not consistently identify the same star as Sigu Tolo, and some scholars argue that modern astronomical ideas entered the tradition through cultural contact.
Thus, Sirius is the standard quiz answer, while the historical evidence behind the alleged astronomical knowledge requires caution.