The onion woman
Once upon a time there was a wicked peasant woman. When she died, she did not leave a single good deed behind, so the devils took her and plunged her into a lake of fire.
Her guardian angel stood and tried to think of some good deed she had performed so that the angel could plead for her before God. Finally, he remembered something; it was not a very big thing, but it was something with which he could plead her case before God.