How is the plague personified

How is the plague personified

My general question is: how is the plague personified? And, is there some psychological or perhaps religious benefit to be gained from personifying the plague? Is this process something like the process that leads to the creation of fairy tales and myths? (If you want to look into this, what is Bruno Bettelheim’s explanation of the meaning of fairy tales.)

Do fairy tales only have meaning for children? More specifically, in the image of the 6th plague of Egypt visited upon the Pharaoh — What do you make of the fact that the Pharaoh is represented as a medieval king? Did this provide some kind of meaning for the people of 14-century Spain who made the image?