"누가 나라며 그린 그림이라는데... 누굴까? 누구지?? 손가락을 분질러버려야겠다." "It is supposed to be a picture someone drew of me... Who could it be? Who?? I think I will break those fingers." "누굴까?" and "누구지?" have the same meaning - "Who could it be?".