Harvey!

Harvey is shown as a kind, bubbly person, offering to give you money every time you click him, and encouraging you to keep going. Even when he's feeling pain from being poked with a needle by the player, he continues being nice and giving encouragement, albeit nervously. However, later in the game (in the Bad/Neutral Ending route), he will start to act more pathetic and desperate the more he's hurt, pitifully whining, begging the player to stop and even offering to give them "whatever they want". This behaviour continues until you unlock the Knife, at that point (when you are locked into the Bad Ending) he will start insulting you, acknowledging that he can't fight back and mock you for willingly injuring him. He will even get hostile and attempt to kill you.