Football Uniform.
Or footballl jersey & jeans Football.

This is easy, but you have to own or be able to borrow a football uniform. Put on the football pads and uniform as you would usually do. Do not wear cleats if you are going out trick-or treating. For a great affect apply black makeup under both eyes. If you are going to a party and not trick-or-treating you could carry around a football for effect.Also if you want to wrap some gauze or adhessive tape around one hand that adds to the costume.

Thanks for the photo Jacob!