This is my first 1 command creation so I hope you like it! Get the command here: here. When you paste that into a command block and activate, you wait ~30 seconds. Text will appear saying "Zombie Health Mod Installed". After that, any zombie in the world will have 10 "O"s above their head. This represents their health. When you hit it, one "O" turns into a lowercase "o". As you might have guessed, an "O" equals a heart, and an "o" equals a half heart. This took me around an hour or to, so I hope you like this a lot!