Boo! There were spooky surprises in store this week when Instagram's most chic got wicked with their fashion. Our favorite snappers like Alexa Chung, Poppy Delevingne, Joan Smalls, and Derek Blasberg looked scary-good in their haunting designs as they prepared for Halloween in over-the-top style. Click through to see this week's best shots, and don't forget to keep up with our editors by following us at popsugarfashion!
Fashion's Most Fabulous Halloween Costumes