What an ironic story...There is no lack of examples of such in reality.
A short summary based on my own understanding:
There was a farm controlled by human being. The old mayor of the animals told other animals a strange dream that he had and asked them to have a revolution so that human beings (farm owner) can no longer "consume without producing"
Here came the revolution. All animal fought for the common good and strived to create a more equal farm where everyone worked hard for their own benefit. They succeeded and the farm was called "animal farm", a farm owned by all animals.
[Revolution to fight capitalism]
They created Seven Commandments stating seven things that animals should not do, like not sleeping in bed, not drinking alcohol, not killing animals... Everyone worked hard and they were happy that they worked for themselves rather than human beings. Pigs were the leaders and supervised the work. Pigs alsodrafted up revolution and others voted.
[Still a utopia -- ideal of Communism ]
There were two pigs trying to be the leader - Snowball, who genuinely tried to improve life of everyone and suggested to build a windmill and Napoleon, who simply wanted power and rejected the windmill plan. While the latter failed to get support, he trained up dogs to scare Snowball away and get power. Snowball was exiled. Since then, everything good happened, credits to Napoleon and anything bad caused by natural disaster or the insufficient planning of Napoleon, Napoleon claimed that it was Snowball's false. "Comrade Napoleon is always right" Some animal claimed that they did a good job thanks to the guidance of Napoleon. Like hens said more eggs were produced thanks to Napoleon.
[Cult of personality and persuit of power]
After that, Napoleon killed pigs that didn't support him in a meeting by claiming that they were spies. Confessions were required and those who did that were killed. Some animals remembered the Seven Commandments that no animals should be killed. When they checked that, it was changed into " no animal should be killed without cause" Animals thought it was like that at the very beginning because the most of them were illiterate. Whenever being questioned, Napoleon asked if the animals wanted the farm owner back. No more questions raised.
[ public execution to bring fear so that no further revolution held against the leader. Change of rules for leader's own advantages. Make use of the uneducated crowd]
The pigs, the leadership group and especially the supreme leader, Napoleon enjoyed more and more privilege. Sleeping in beds, wearing clothes, drinking alcohol, having better food...(Things considered not animalism and were disallowed)
[Exploitation of power]
Meanwhile, animals except pigs worked even harder and had less food but they were still willing to do so given that they worked for themselves. Pigs tried to convince others with figures that the output of crops increased every year. The crowd believed so.
[exaggeration of food output and took advantage of the crowd. Instead of working for human, now they work for the pigs]
Gradually, The Seven Commandments were gone and a single Commandment was added. It ran:
"ALL ANIMALS ARE EQUAL BUT SOME ANIMALS ARE MORE EQUAL THAN OTHERS"
[Abolishment of the communism ideal - contradicted communism itself]
At the end, animals found the pigs walking with two legs, wearing clothes and chatting happily with other farm owners on how to make animals willingly worked harder and ate less...
[Transformation to capitalism]
