You want a broader audience then remember America loves penguins right now. I have been throwing around an idea to show how bad ass the penguin can be. Some client of his makes a scene at his "ice berg" club/ diner/ whatever and trying to make the message clear to Cobblepot shoots one of his penguins he has in his large tank/pool in the middle of his restaurant. Everyone will hate that villian so much and when Cobblepot replys to the message it will be so shocking, so unexpexted that people will litterally be thinking "Holy ****, I would never want to **** with the Penguin"
Just when it appears that the Penguin is the number one guy in town, the Joker will arrive the audience can feel the tension and the potential for absolute oblivion when these two huge forces collide. In a brief but intense exchange of dialouge it would appear the Penguin has maintained his place on top, then the Joker poisons all of the Penguin's penguins, or have them all embowled or skinned or mutalated in some fashion that makes you hate the Joker, making Oswald adhear to the Joker's demand for some weapon Oswald has been holding out on.
That would show the ruthlessness of both characters and put the Joker over everyone else.
Joker can actually be the one who coins the name "Penguin."