Osiris is one of the most prominent gods of the Ancent Egypt, usually depicted as a mummified king, complete with the ceremonial curved beard, crown, flail and crozier. His skin is generally green or black, to represent his association with the dead.
Once he took form and lived upon earth, his brother Set murdered him out of either jealousy or rage and scattered his remains across Egypt. Ra took pity to his death and sent Anubis to prepare for the first ever mummufication, however, the ritual is not sufficient to bring him back to the world of living, instead he stayed in the underworld to oversee judgments for the deceased.
The deceased had to be judged at the hall of judgment with their heart weighed against a feather, Osiris will welcome them into his world if they are considered “balanced”.
Osiris represents the belief in rebirgh and their feeling that order and justice preserved beyong the grave.