You can also buy bags of zombies from Twilight Creations without having to buy the whole game. (At least you used to be able to do this. I haven't checked recently.)
Of course, Zombies!!! is an awesome game and easy to play, so you probably want to buy the whole thing.
Marv / FinarvynKnight of Dangerous Quests,
Labyrinth Lord Society, 2009
Author of the
S&W White Box 2009
Old LL board member #007 (back in 2007)
Earl of Stone Creek / C&C Society Member since 2003
OD&D player since 1975