In a recent session of our Age of Worms campaign, the characters encountered a trio of mimics. For many of the players, this was their first encounter with these truly old-school D&D monsters. That is one thing I’ve particularly enjoyed about Age of Worms, it exposes the party to some of the classic monsters that us veteran players were fighting against back in our youth. We’re in the fourth adventure now and have already encountered chimeras, doppelgangers, elementals, ghouls, grimlocks, invisible stalkers, kobolds, lizard folk, mimics, skeletons, trolls, and zombies, just to name the old-school critters.
Recently, Wizards of the Coast published an article discussing the evolution of the mimic (and other shapeshifters) through the various editions of Dungeons & Dragons. If you are interested in such, it is worth the read.