If you've ever seen Jimmy Fallon's "Ew!" series on The Tonight Show, you know how ridiculous he gets as Sara, the blond teenage girl who hosts a talk show with her besties in her basement. It's about to get even more ridiculous when Swift becomes the latest celebrity to get in on the fun. In a video uploaded to the show's YouTube channel this week, Swift dons glasses and fake braces to channel Natalie, whose mom was best friends with Sara's mom in college. Check out Swift's video below for a taste of what's to come when she stops by the show on Wednesday, Aug. 13.