Actually, I spent a week on making this exact script. It's not nearly as easy as it sounds, also setCreatureName isn't a function. The only things I can tell you is that you will either need to source it, or if you're gonna Lua script it, you will need to basically create the monster.xml every time the creature is created. Even if you lua it, you will still need to source the text sent when you're attacked.
I'd say the easiest thing you can do if you're not skilled in Lua is to just use the Shadow Clone Jutsu. I apologize for not being able to release the script, but I spent way too much time on making it, and I'd rather it be unique.