Card evolutions, or retrained monsters, is the term used to describe a monster that has been reprinted with a new effect and slightly different name, but with the same base ATK and DEF, and usually Level and appearance as well. Examples include "Battle Ox" to "Enraged Battle Ox" and "Magician of Black Chaos" to "Dark Magician of Chaos". Special cases are "Harpie Lady 1", "Harpie Lady 2", and "Harpie Lady 3", which all have the same stats as the original "Harpie Lady", but are not all representing the same creature. Rather, they are the three sisters from "Harpie Lady Sisters".