For this Dark Knight Joker costume, you’ll need to put in a lot of work and effort in order to get everything right down to the last detail. If you plan to put this costume together on your own, then make sure that you either get a Joker mask (hair and all) or get a friend of yours (who is very good with makeup) to put on the makeup for you. If you feel up to the challenge, you can always put it on yourself! Make sure that you have a long purple coat and that you wear a dark green vest underneath it. If you have Joker gloves, then you can also choose to wear those with your costume as well.