Chaotic Shiny productions has a lot of great generators, including this one, up on their website for free. Just click on the Publisher Homepage link to the right. By providing the free generators for download, they can help you run games when you're away from the Internet.
The zombie generator includes all of the bells and whistles we've come to expect from CS: you can edit the text generated, copy and paste it into other game materials you're preparing, and voila! You've got a solid description of several individual zombies. One thing that's difficult in a zombie game is that dangerous situations are normally about hordes of zombies, making horrific descriptions of individual zombies fade into the background. The Zombie Generator is appropriate for situations in which someone unexpectedly opens the door to a closet and a zombie falls out, or a zombie is found to be inside the safe house, or comes crashing through a window, and the presence of just one zombie provides the horror and danger of the encounter.
It's free, what do you have to lose! Check it out, you won't always be on the Internet (if you do, you DO have Chaotic Shiny bookmarked, right?)