What shocking behavior do the pigs exhibit at the end of the novella?

At the end of the novella, the pigs walking on two legs is a shocking and significant behavior that symbolizes the complete transformation of the pigs and the betrayal of the original ideals of Animalism. This act represents their total assimilation into the human world, which they initially sought to overthrow. By walking on two legs, the pigs signal that they have become indistinguishable from their former oppressors, showcasing the corruption of power and the cycle of tyranny. This pivotal moment underscores the central theme of the novella regarding the dangers of totalitarianism and the ease with which those in power can abandon revolutionary principles for personal gain. This behavior specifically highlights the irony of the revolution's failure and serves as a commentary on how a new ruling class can emerge, mirroring the old injustices.