Beasts of England, Beasts of Ireland,Beasts of every land and clime,Hearken to my joyful tidingsOf the Golden future time.
The main characters of the story, in the setting of it.
The windmill is destroyed, causing the pigs to revolt and go against everyone else - creating a pig ethnostate. Which is ironic, considering there were other animals in the farm.
The Battle of Cowshed - the turning point in the main conflict, and a victory for Napoleon.
A new rhetoric is formed - four legs good, two legs bad. This could be interpreted with many real-life views, as that is what the book is based on. Segregation and alienation of two-legged animals is encouraged.
The farm gets a new windmill. This windmill brings in a period of prosperity for the farm and allows the pigs to live comfortably and well. This causes them to completely change how they act and their actions.
Seeing the new period of prosperity, the pigs loosen up once again. They cease the "four legs good, two legs bad" rhetoric, instead replacing it with "four legs good, two legs better". They soon look out the mirror and are indistinguishable from the humans who once exploited them.