In Egyptian mythology, Geb (or Seb) was the god of the earth, son of Shu and Tefnut, brother and husband of Nuit, and father of Osiris, Set, Isis, and Nephthys. In the earliest stages of Egyptian history his name was Geb; in later forms of the language it became Seb, but the old pronunciation has become so common in popular works on the subject that it is used herein. His sacred animal was the goose, and he was often referred to as the "Great Cackler". He is generally represented as a man with green or black skin - the color of living things, and the color of the fertile Nile mud, respectively. It was said that Seb would hold imprisoned the souls of the wicked, that they might not ascend to heaven.
[Source: Shawn C. Knight, "Egyptian Mythology FAQ" ]