Supergirl To The Rescue Supergirl has all the powers Superman gets from our funky yellow sun. Though she certainly has a more spunky fun time defeating the bad guys. So, it’s no wonder why so many girls want to dress up as Supergirl for Halloween trick or treating as well as defeating imaginary bad guys in the backyard. If you’ve been dreaming about becoming Supergirl this Halloween, then this officially licensed costume might just be a dream come true. A Complete Supergirl Costume This officially licensed Supergirl costume is complete. It includes the dress with a removable cape and a stylish belt. The costume is made from professional-quality fabrics that are easy to clean and refresh. It is available in girl’s sizes small, medium and large.