"The Adventures of Little Boy and Pillowfart!"

"It's one of Twain's lesser works."

Little Boy came into the living room after playing outside. He saw his friend Pillowfart sitting on the sofa reading a large book.
"What are you reading, Pillowfart?"
Without looking away from his book, Pillowfart answered, "It's called 'Quasi-lateral Differentiated Aspects of Multi-Faceted Ultraphysics."
"What?! I think you just made up a bunch of words to sound smart."
"Nope," Pillowfart said. "I'm actually quite scientificous."
Little Boy crossed his arms and put the test to his friend:
"OK, smarty pants, so what's the book about?"
Pillowfart lay the book in his lap, held his chin with his hand and thought for a few moments.
"It's about a horse named Dave who loves to eat flowers, but he eats so many that one day he farts, and the fart is so big that it launches him into space, and he doesn't stop until he reaches Mars. So it's about the first horse on Mars. Yes. That."
Little Boy put his hands in his pockets and looked down to the ground, thinking he had been rightly humbled.
"Oh, OK. I guess you really are smart. I'm sorry I doubted you, Pillowfart."