Fox Patronus

Imagine a nice stroll through the forbidden forest; you're simply minding your business, smelling the bark and leaves, your wispy cloak strokes the branches as you pass. A lovely evening.

Oh? And what's this cute little critter whomst approaches from the underbrush? A rabbit, perhaps?

Now it's running.

Okay, now it's really running.

It's a fox! Not only that, it's a blue, ethereal fox form, which is currently charging (seemingly) in your direction! It bounces around some felled trees and leaps at you!

You've decided, at this point, that enough is enough. The souls of unsuspecting passersby will have to wait for another night; it's time to take your business elsewhere. You take to the sky and high-tail it back to Azkaban for some peace and quiet.

Just another day in the life Stuart the dementor.