Harry Potter: Slytherin Knitted Christmas Sweater The red and green action on this Harry Potter Slytherin Knitted Christmas Sweater ($55) makes it look especially festive. Slytherins are not necessarily cold-blooded like snakes, but they'll still appreciate a little extra warmth this Winter. Image Source: merchoid.com Harry Potter Slytherin Knitted Christmas Sweater $55 from merchoid.com Buy Now