Harry Potter Slytherin Sweater Dress. Keep warm on the sides of the Quidditch pitch with this cozy sweater dress from Harry Potter. Made in Slytherin colors with the house crest patch on the right sleeve and a "S" patch near the left hem. Layer over leggings, boots and under your robes for the ultimate Slytherin look. 100% acrylic. Wash cold; dry flat. Oversized fit.