Witches, as a motif, entered the history of art around 1500. The oldest item that seems to have survived is a 1497 print by Dürer, the girl in the older Love Magic painting cannot be considered a witch. But it was Dürer’s student Hans Baldung Grien who really exploited the topic, in this painting and numerous prints and drawings.
There are several reasons why he may have loved this subject. One less obvious is that he was, far more than his teacher, interested in natural poses, and the anatomy of the body in motion. Some of his witches have poses that wouldn’t make much sense in any other context. This painting is rather static, but note the legs of the witch on the left. His Judith has the same pose. It’s a natural way of standing relaxed, though only when leaning against something. In painting, it may have been a first.