So I had this general idea for some t-shirt design featuring a zombie, but thought I needed a zombie face to do it. A quick search for zombie clip art wasn't turning up anything I really liked... at least not anything free.
I've been finding that if I'm willing to invest the time, I can do some halfway decent stuff with Inkscape. It's like Adobe Illustrator, only it's free. It doesn't have all of Illustrator's functions, but it has some Illustrator doesn't have. So I drew a cartoon zombie face which I've contributed to the Open Clip Art Library.
This means I, the author of the Cartoon Zombie Face, have placed it into the public domain. You can use it however you want, whenever you want, wherever you want. You do not need my permission and you don't even need to credit me (though credit and a link back here would be nice). And I guarantee it is public domain because I drew it and I'm putting it out there.
The image above links to a 997 x 1161 pixel .gif you can download. If you want a vector version (can be used in Illustrator or Inkscape to create extremely high-resolution versions) right click this link and "save link as" for the file in .SVG format.