Anubis is the Greek name for the ancient Egyptian jackal-headed guardian of the dead, who took souls to the Underworld and protected them on their journey. He also weighed the heart of the dead against the feather symbol of Ma'at, the goddess of truth. One of the reasons that the ancient Egyptians took such care to preserve their dead with sweet-smelling herbs was that it was believed Anubis would check each person with his keen canine nose. Only if they smelled pure would he allow them to enter the Kingdom of the Dead.
Anubis was portrayed as a jackal-headed man/god, or as a jackal wearing ribbons and holding a flagellum, a symbol of protection, in the crook of his arm.
As one of the most important funerary rites in Egypt involved the process of embalming, so it was that Anubis became the god of embalming. High priests often wore an Anubis mask to perform the ceremonial deeds of embalming. It was said in the Book of the Dead that it had been Anubis who embalmed the body of Osiris (which would make him the older sibling of Horus).
No public procession in Egypt would be conducted without an Anubis to march at the head, the "go-between" of gods and men. The ancient Egyptians swore "by the Dog" when making oaths they would not break.
— Adapted from Wikipedia
