Broadly adapted from George Orwell's classic "Animal Farm", this book narrates the transformation of fairly happy, functional farm, taken over by a bunch of farm animals led by some pigs, who succeed in driving away the 'human' masters who once ran the place.
The rebellion, generally successful at the start, degenerated into a system dominated by the pigs, led by a pig named Napoleon and some of his loyal pig supporters who usurped all power even as they propagated their hatred of the "humans'.
Eventually, the pigs morph into somewhat human animals, leading to a climactic end of the story.