I love me some zombies. So please pardon the interruption with non-licensed set news, but if you wanted to get some zombies for your monster fighters to... uh, fight, then 9465 The Zombies
ought to do it. It is a Target exclusive but you can buy it from Shop@Home right now. It will cost you $39.99 for three zombies, a zombie fighter, Mjolnir, a hammer truck and a pair of sarcophagi.
Hammers: the preferred weapon of Zombie fighters everywhere.