Do you know any zombie models that do NOT attack other zombies and don’t have a ton of scripts? The problem might be that the zombie has a lot of scripts.
I would recommend coding your own zombies. Perhaps you want pathfinding. That would depend on how many zombies there are at once. It also depends on how you want the zombies to operate. Is it a round based game like Black Ops Zombies? Is it an open world zombie survival game where zombies spawn somewhat randomly?
It is like an extra minigame
s in a tycoon. I have no idea how to script a zombie
Also I am using the tall lifelike zombie from roblox.
Still lags. 
Dang, I think it’s the zombie then, I’m all out of ideas.