I've probably mentioned it before, but a favorite television show in our house when I was growing up was The Cosby Show. Heathcliff Huxtable was such an interesting dad, a combination of stern but quirky. One of this quirks was that he hated when the kids left the refrigerator door open. He would yell to them, "Quick! Shut the door! Or else the penguins will get loose!"
I have adapted the penguins into my parenting because I've learned that a kid will sit in front of the fridge with the doors open for a half hour, if you let him. We have a fridge that beeps to let you know that it is open. Yes, it can sometimes be obvious as well annoying (when you're just trying to get the groceries put away!), but it is good because the main compartment has French doors that if you don't close one at a time don't shut all the way and you wouldn't want that milk to go bad.
Charlie now believes that the incessant beeping is the sound of penguins attempting escape! He yells at me to hurry and shut the doors or else they'll get out. I try to tell him that I just need to put the eggs and cheese away and then I'll shut them. He cannot be dissuaded from his mission. The penguins cannot come out.