If you create any original work, be it art, writing, a song or recording, a film or photography copyright law automatically grants you limited copyright protection to your work. Additional protection, which hinges primarily upon raising the ceiling for actual damages and providing the opportunity to pursue punitive damages in a civil case, is granted for content creators who register their work with the Copyright Office in the Library of Congress.

Determine if the Straw Man is copyrightable. You may only register original work with the copyright office and the piece must be a creative endeavor. Phrases and everyday imagery may not be copyrighted, though if they’re used in conjunction with commerce, you may be able to apply for trademark status for the Straw Man. Trademarks are granted by your state’s Secretary of State as well as the Patent and Trademark Office.

Source: http://www.ehow.com/how_6889820_do-copyright-straw-man_.html