A character who is undergoing changes of personality (like buying off mental disadvantages - flaws - or changing alignment) might confront personifications of aspects of his personality in dreams: a griffon representing the courage he needs to face a terrible foe, or a satyr standing for the lecherousness a warrior must overcome to be admitted to an order of knights who must uphold vows of chastity.
As you travel through the thick growth of a forest, a great shadow suddenly moves over you. You raise your head fast, but whatever it was, it was faster. However you try, you don't see anything, and nothing approaches you. Maybe it is better so.