Omnicide is the premier zombie co-op and singleplayer modification for Battlefield 2 (A.K.A. BF2). This modification features an authentic zombie environment, with new and top-quality maps, weapons, skins, sounds, and chillingly authentic voice acting. In this modification you must think to survive and work with your teammates. It features two gamemodes: Survival, a new idea to BF2, where you and your comrades defend yourself until you are finally overcome by the zombies, and Escape, where you and your comrades fight to escape zombie hell. Give this mod a try, and you'll be amazed at what the Omnicide developers have done with Battlefield 2.
I would say the best zombie mod all of BF2, but there have been very little zombie mods for this game. I will however rank it in the top few of my favorite BF2 mods because of its authenticity and suspenseful gameplay of zombies coming at you non-stop. :D