zombie mode

With the Leader Pass (notably the Rulers of China DLC) zombies were hit with the nerf stick. Previously, zombie Mutation Strength would increase by 1 for every zombie killed. So kill 10 zombies and they get +10 Mutation Strength. (I think you can see this is how they very rapidly gained...

What the title says. It happened every single time I dug an artifact in my first zombie mode game. If the artifact is at sea (shipwreck) a zombie unit will spawn in the closest land tile available. Keep it in mind in case you have other units and/or cities around.