Fight some crime in this heroic costume kit As the crime-fighting Dark Knight, you can defeat the Joker or team up with Robin in this daring getup. The Batman T-Shirt Adult Costume Kit is ideal for those who want to dress up without all of the hassle. The kit comes with a cotton old-school batman shirt with a black cape. In order to hide the fact that you are really Bruce Wayne, the costume kit also comes with a mask.