Which former adversary of Animal Farm is seen cajoling with Napoleon at the end of the book?

At the end of "Animal Farm," former adversary Frederick is not present, but Napoleon is seen interacting amiably with Mr. Pilkington, the neighboring farmer. This symbolizes the betrayal of the original revolutionary ideals, as the animals realize that the pigs have become indistinguishable from the humans they once opposed. The camaraderie between Napoleon and Pilkington highlights the corruption of power and the cyclical nature of tyranny.