There’s a very clear transition from a positive to a negative mood in the novel Animal Farm, mirroring the plot's development from the story of a brave uprising to a cautionary tale about corruption. Initially, the mood is optimistic and energized as the animals band together to overthrow their human oppressors. They are fueled by the promise of equality and a better life, which the pigs lay on thickly. This early mood makes their battles and struggles seem like a necessary part of revolution and change, instilling a sense of hope and possibility in the reader. However, as the story progresses, the mood becomes increasingly tense and somber. The reader is drawn into the animals' experiences of injustice and powerlessness as the pigs gradually co-opt power and control. The novel generates deep sympathy on the part of the reader for characters like Old Major and Boxer. These well-meaning figures embody the noble but ultimately exploited ideals of the revolution, showing how it “could have been.” This engagement in turn pulls the reader into a more emotional connection with the animals who are left to suffer under Napoleon.
The mood darkens considerably as the farm careens toward a total takeover by the pigs. By this point, the pigs are also being more overt in their use of propaganda, manipulating and controlling the other animals openly. Despite the animals’ best efforts to keep faith that their leaders want the best for them, disillusionment and discontent quickly take hold. The mood reflects this transition, filling the reader with a creeping sense of dread. By the novel’s conclusion, the mood is grim and contemplative. As the pigs and the humans become indistinguishable, the animals realize that they have ended up exactly where they began: powerless prisoners of corrupt leaders.