I am trying to make a game where you switch what exists, and I have a script that puts things back and forth from replicated storage. However, if I try to copy a zombie from replicated storage, it's scripts break. Is there a way to make a local zombie that doesn't affect other players, and is also only affected by parts on the client side?
You have to control the zombie's AI VIA LocalScripts, keep in mind that they only operate in the player's object, character, and tools, so placing LocalScripts inside of the zombie is not going to work. Logical thing is to create a zombie on the client with a name which has a "zombie id" then a new LocalScript inside of the player object to control that specific zombie id.