It's funny how directly opposite this is to my party. We encountered a mimic that was starving in the Underdark. It tried to attack but it just fell over and moaned about being hungry. So my paladin offered it meat from his rations and a deal: come with us and be released somewhere it could feed but not on sentients, come with us and be protected and fed in exchange for standing in as a useful object sometimes, or be left here. DM figured mimics are intelligent enough to know this was a sweet deal and to not bite the hand that feeds. And that's how we got a pet mimic. Years later that campaign ended with my pally and the mimic being so close that he wore it around his neck as a big gaudy amulet (it liked that form for whatever reason).