If you want something innovative then how about no monsters at all? Look at UnrealWorld for example, there are no monsters but animals and people. Very few of them are hostile to begin with.
Another approach is to not limit yourselve to a single pattern for enemy. Cataclysm: DDA started with simple zombies, then pretty much all special zombies from L4D were added, later expanded to twice of that with different variations of special zombies, then triffids and fungals where added, mutated and zombified animals, trans-dimensional creatures and perhaps worst of all of them - unpredictable NPCs. With such setup you don’t really care how those guys are called, the variety of enemies in their behavior and individual danger outweighs “yet another zombie setting”. You can avoid stigma to a large degree if you design your enemies properly, make them behave in such a way that player has to use different tactic to survive. L4D did a great job wheres DayZ completely missed in that department.
Important detail here is not how they look and what specifically they do, but if they require player to behave differently to avoid them or fight them.