Harry Potter: Hogwarts Crest Christmas Ornament. Hogwarts will always be there to welcome you home. Adorn your tree with this Christmas tree ornament featuring all four house crests—Gryffindor, Ravenclaw, Hufflepuff and Slytherin—for the distinguished School of Witchcraft and Wizardry. Hallmark Ornaments are a great way to commemorate hobbies, life events and individual interests in entertainment, sports and more. Each festive and collectible ornament is perfect for sharing with family and friends.