Arachne believed that her weaving skills were much better than the goddess Athena's, so she challenged the goddess to a weaving contest. Although Arachne's weaving was better than Athena's, she wove a scene depicting the Greek gods and goddesses behaving irresponsibly. Of course, this angered Athena, as she was a goddess herself, and so she cursed/turned Arachne into a spider to teach her to be respectful.
