Many times, in scripture when the covenant people interact with the surrounding populace, things happen that find meaning in local mythology. By this I do not mean that it supports local mythology, but like in the book Eternity in their Hearts, it seems God demonstrated truths to people using things they already believed.
In Exodus we see Moses strike the Nile and the water turn to blood. It is commonly held that each of these plagues was against some element of Egyptian religion—for example the Nile was seen as sacred. However, I wonder now if this did not have to do with the ancient Egyptian belief in Hathor’s Destruction of Mankind. According to this story the god Re declared a judgment on mankind for rebellion and sent Hathor to destroy them. During the judgment Re changed his mind and inundated the land with a “red beer.” Hathor, because of its similarity to blood, saw it as a sign of the success of her mission but got drunk and forgot to kill the rest of mankind. It seems likely that this plague in which the Egyptian people were judged and harmed by something similar to their mythology showed the powerlessness of Re and his human representative, Pharaoh.