Your Holiday Quest

You wake up feeling a bit fuzzy and not quite yourself. There's also a strange blue glow in front of your face and something strapped to your back. You try to stand, but you find yourself forced down on all fours. After a bit of a struggle you manage to make your way to the bathroom to see your reflection, but instead of seeing yourself in the mirror, you see a reindeer with a glowing blue nose and a saddlebag filled with presents! As you try to get your bearings and figure out what happened, you notice that pinned next to the mirror is a strange letter...