kibitzer

noun

1. A person who offers unsolicited views, advice, or criticism; one who kibitzes.

   “Did I ask you what you thought about my cards, you kibitzer?”

   “"Don't be a kibitzer!" Grampa snapped. "When I need help, I'll ask for it. No dad-blamed machine is gonna outthink Grampa!" He snorted indignantly.”

   “Neither good nor evil exactly, he is the ultimate catalyst or kibitzer, a blue-note howl of pain and laughter such as Charlie Parker might have blown.”