Pirate sword. Use a full page of a news paper (really 2 pages). Roll diagonally. Tape closed. Flatten bottom third and fold toward "blade" to make handle. Tape. We used old CDs for the hilts instead of cardboard and let the kids decoarte with sticky jewels.
DIY Pirate Sign on a Budget - Even if you don't want to follow all the steps in the article, you could do something similar on the wall with paper. Either way it'd be a great addition to the pirate classroom theme!