"Right then everyone!" Harry cried, clapping his hands together to draw the classes attention to him, "Today we’re going to be learning about the patronus charm," there were murmurs of excitement, "As you should hopefully all know, the patronus charms is an extremely difficult piece of magic to master, and is the only defence available to you should you encounter a dementor (as well as a few other magical creatures but as I sincerely doubt any of you will stumble across a Lethifold in your life, we’ll not worry about it now)," only Hermione offered him anything but a blank stare, "Uh - anyway! The patronus charm takes two forms - the first is a kind of white silver mist, but the most difficult to master is the corporal patronus, which takes the form of an animal with which you have an affinity for.