Napoleon is a malevolent leader because he becomes a dictator. For, as such he defeats the entire purpose of the animal's rebellion against the selfish Mr. Jones. Chapter 5 portrays Napoleon as a dictator:
Napoleon, with the dogs following him, now mounted on to the raised portion of the floor where Major had previously stood to deliver his speech....Sunday Meetings would come to an end. They were unnecessary, he said, and wasted time. In future all questions relating to the working of the farm would be settled by a special committee of pigs, presided over by himself. These would meet in private and afterwards communicate their decisions to the others
In fact, with Napoleon as their leader, the animals are worse off than they were with Jones:
- Unlike Snowball, who designs a windmill which will alleviate the work of the animals, Napoleon increases their work.
- He changes policies. In Chapter 6, for instance, Napoleon announces that Animal Farm will engage in trade with the neighboring farms where there are, of course, humans.
- He rewrites the Seven Commandments and eliminates the anthem, Beasts of England, contending that the Rebellion is now completed and the song has no purpose. Singing the anthem is forbidden.
- Squealer interprets events for the animals. He is the head of Napoleon's propaganda.
- Some animals are accused of being traitors and are executed.
- Napoleon tricks Boxer into going into a truck that supposedly will take him to a hospital when he is really transported to the glue factory.
- He enforces his wishes through brutality; his ferocious dogs attack anyone who dissents. Thus, he rules by military force as most dictators do.
- He does no work himself, and he goes to live in the house and sleeps on the beds. Napoleon even drinks and walks on two legs. Clearly, he places himself above the other animals.
As a dictator, Napoleon is mainly concerned about consolidating his power, eliminating those that oppose him, and controlling the information that the common animals get in order to be sure that they yet believe he is benevolent.