A boy is assigned homework to have his parents read him a bedtime story.
Upon reaching home, his father reads him a variation of the "Three Little Pigs."
The story covered everything from the threat of the wolf, to the new addition of the pigs buying their materials, to the pigs defeating the wolf. In class the next day, the teacher asked the boy what the man selling sticks thought when the pig came to his door.
The boy promptly answered, "Holy cow, a talking pig!"