Four Sons of Horus
The Four Sons of Horus protected the innards of the deceased. In the Pyramid Texts, they help the king ascend to heaven. By the New Kingdom, the four are associated with protecting the body of Osiris and with the constellation of the the Great Bear.
From the late 18th Dynasty, the four are represented on lids of canopic jars (earlier canopic jars had human heads). When shown on coffins, Hapy and Qebehsenuef appear on the west, and Imsety and Duamutef on the east.
Dodson, A. 1994. The canopic equipment of the kings of Egypt. London.
Taylor, J.H. 2001. Death and the Afterlife in Ancient Egypt, London, 67-68.