Both the primeval being and the creator god of Heliopolis, Atum was usually represented as a human being wearing the double crown of Upper and Lower Egypt. His mythological origins placed him at the head of the Ennead of Heliopolis. He begot Shu (the air) and Tefnut (moisture). They in turn were the parents of Geb (earth) and Nut (sky) and grandparents of Osiris, Isis, Seth, and Nephthys. Atum is sometimes joined with the sun god Ra as Ra-Atum. In later periods he was worshipped as the evening manifestation of the sun god Kheperi, who was the morning manifestation. He is sometimes associated with the setting sun, the primeval mound where life began, the scarab, beetle, and a serpent.