"The world egg, cosmic egg or mundane egg is a mythological motif found in the creation myths of many cultures and civilizations. Typically, the world egg is a beginning of some sort, and the universe or some primordial being comes into existence by "hatching" from the egg, sometimes lain on the primordial waters of the Earth.[1][2]"- https://en.wikipedia.org/wiki/World_egg

This may help.