What type of payment did Napoleon receive for the timber from Frederick?

Napoleon received fake money for the timber from Frederick, which is significant in the context of the story. This transaction highlights themes of betrayal and manipulation within the narrative. The payment method is a critical plot point, showcasing Frederick's deceitful character and the overarching message about the dangers of naiveté in trusting others without skepticism.

By accepting fake money, Napoleon is ultimately being duped, emphasizing the vulnerability of the pigs' leadership and their miscalculations concerning human nature. The fake money transaction symbolizes the larger issues of exploitation and dishonesty that are central to the novel's critique of power dynamics and the corrupting influence of ambition. This event serves to illustrate the consequences of misplaced trust and the harsh realities of the capitalist exchanges that the animals sought to escape from.