In Animal Farm, there was no ultimate victory for the animals, with the exception of the pigs. While the animals realized their dream of overthrowing Mr Jones, life for the majority of the animals on the farm was just as hard and oppressive under Napoleon as it was when humans ran the farm. By the end of the novel, for example, Boxer has been sold to a glue manufacturer, the animals work seven days per week and retirement is nothing more than a dream. In addition, the Seven Commandments, which were designed to promote equality and freedom, have been reduced to the following single commandment, which demonstrates pigs' belief in other animals' inferiority:
ALL ANIMALS ARE EQUAL BUT SOME ANIMALS ARE MORE EQUAL THAN OTHERS.
As for the pigs, they replaced their human master, Mr Jones, and became equally tyrannical and selfish. They live in the farmhouse, drink alcohol, wear clothes, and enjoy better rations and living standards than other animals on the farm.
Just like Mr Jones, Napoleon rules the farm with an iron fist, as we see from his expulsion of Snowball, and his rise to absolute power is, arguably, the only time a character experiences a long-term victory in the novel.