http://www.splitreason.com/product/580
Have a few ideas. Know that optical illusion with text in blocks?

(Stand back a bit)
Could have the same thing that says. "If you can read this, then you've seen me coming. Kudos for you!"
Could have hoodies with one's best score / kill written on the back.
How about something scary?

Wait... why are we even looking into this? Lets just get some arts students in on this thing!
Dear arts students. I'll give beer money to whoever comes up with some sarcastic hoodie designs for the guild. Out of my own pocket.
All suggestions welcome. The final decision will probably be taken by the exec. To the drawing board!