Look, mimics are smarter than you or me. It says right here, it's canonical, it's in the big book of truth:

This means they could be ANYWHERE. They could be ANYTHING. They could be ANYONE. The Dragon Emperor has decreed that something must be done about this, and that's now your problem. How are you going to solve this? Is the twist that you're secretly all mimics too? Maybe the Emperor's a mimic?
Have your dice started eating each other yet? Have you counted them recently?