>That wouldn't be very fun.
you clearly don't think big enough. dungeons are horrible places for mimics, you get one decent meal every how long? now just imagine. an adventurer comes by and discovers what he thinks is a magic talking chest, capable of sorting everything he places inside or spitting out whatever he asks for all on its own. he figures, "hey this thing could be pretty useful" so he takes it home with him. soon, the adventurer goes missing, and his belongings are given to his next of kin until he returns. but then that person goes missing, and everything is transfered to someone else. eventually you may even wind up in the hands of a member of an assassins guild, who would be more than happy to keep feeding you bodies. after all, it's fewer graves for him to dig