I'm no fan of zombies, far from it. But to be honest, I don't even notice the images up there passes the first time.or two I see 'em.
Also, Aadie's point of "every image is gonna have something somebody doesn't like"
That being said, a tip to Mayo and anybody else looking to put things up. When in doubt avoid things with living (or un-living) people/creatures in it and that'll take care of a lot of "turn offs"
I use art/pictures for my stuff that I add words into via a photo editor (see signature for a few examples)
For the zombie thing, some kind of symbol that the Survivors use might work, even without words.
As somebody who is quite found of making sig-images, I know some things just might not work.