I think in the early editions they said that mimics were only really effective at imitating wood and stone. I agree that mimic chests are done to death but “anything could be a mimic” would get old fast I fear. Limiting them to only some materials but then getting creative within those limits would keep it interesting without it feeling like a cheap jumpscare.
Oh totally. I didn’t mean that as a criticism of the comic, I really like the comic. Your artstyle is very distinct and charming. It just got me thinking about how to run mimics generally. A mimic wizard one-shot sounds like a lot of fun.