The fable of The Chicken and the Pig is about commitment to a project or cause. When producing a dish made of ham and eggs, the pig provides the ham which requires his sacrifice and the chicken provides the eggs which are not difficult to produce. Thus the pig is really committed in that dish while the chicken is only involved, yet both are needed to produce the dish.
The fable of the Chicken and the Pig is used to illustrate the differing levels of project stakeholders involved in a project. The basic fable runs:[1]
A Pig and a Chicken are walking down the road.
The Chicken says: "Hey Pig, I was thinking we should open a restaurant!"
Pig replies: "Hm, maybe, what would we call it?"
The Chicken responds: "How about 'ham-n-eggs'?"
The Pig thinks for a moment and says: "No thanks. I'd be committed, but you'd only be involved!"