Has there ever been a Bad Wolf shirt? If there hasn't then there really ought to be. I mean, if we don't print one, we are at risk of being conquered by the Daleks...
Oh! It would also be cool if you could fit "Drwg Blaidd" in there somewhere. That was the name of the nuclear power plant in the Boom Town episode. It's welsh for Bad Wolf.
And as graffiti.