Okay, two Simpsons references seem appropriate here.

"The animal chain of command goes: mouse, cat,....dog."

- the head exec of Itchy and Scratchy cartoons, explaining to his writers what the new character should be, eventually resulting in Poochie the Rockin Dog.

and, of course, in the meat industry sponsored film strip shown to Lisa's class to discourage vegetarianism:

"No, your friend's not crazy, just ignorant. See, your crazy friend has obviously never heard of the food chain."

-Troy McClure, who then displays a chart-like image showing the silhouettes of every kind of animal all pointing towards the open mouthed human figure in the center.