I just saw what Ari put on her Girl Scout cookie sales page as "My Cookie Story":

In days of yore there lived a witch. Her house was in the middle of the darkest parts of woods. They say it moves, that it's in the dark parts of all forests. They say she grants boons, at a price. In more recent days, there lives a unicorn. No one knows where it came from. No one can stop it, but that isn't a problem. The unicorn hasn't hurt anyone. The unicorn just exists.