A very boringcereal that older animals typically eat for breakfast. Often eaten with a sliced grapefruit or dry toast.
"Fluffy was eating a bowl of fiber paw for breakfast, that cereal looks so boring! There isn't even an animal on the box! Just a black and white paw print."
The sophisticated and dignified manner in which to address someone who's been given the mind numbing task of building cardboard boxes for wine bottles.
At work:
Temp:"What are we doing today?"
Supervisor:"Same as yesterday, building more boxes."
Temp:"How do I put that down in my resume?"
Supervisor:"Write down that you've been a fiber construction engineer."