What are some examples of Napoleon abusing his power in Animal Farm?

There are lots of examples to choose from of Napoleon abusing his power. He abuses his power, for example, by rewriting the past. He convinces the animals that Snowball was an enemy from the start, and that it was he, Napoleon, and not Snowball who led from the front in the Battle of the Cowshed, and he, not Snowball, who was injured in that battle. Napoleon rewrites history like this throughout the story, and this is perhaps the most significant way in which he abuses his power, because it is so invasive. He essentially exercises power over the minds of the other animals.
Napoleon also exercises power over the animals physically. He uses his dogs to intimidate and inflict violence upon the other animals. At the show trial in chapter 7, for example, Napoleon has his dogs firstly tear out the throats of four pigs accused of betraying him and then kill instantly several other animals who confess to minor crimes like hiding ears of corn.
At the end of the scene, Orwell describes "a pile of corpses lying before Napoleon's feet and the air . . . heavy with the smell of blood." Later in the story, Napoleon is depicted carrying a whip in his trotter and standing on two legs. This moment symbolically represents how he has abused his power through violence in the same way that Mr. Jones used to do.

Napoleon initially abuses his power by usurping authority with the help of his nine ferocious dogs, which chase Snowball off the farm and strike fear in all of the animals. Napoleon immediately begins abusing his power by forcing the animals to work long hours to complete the windmill. Napoleon then begins trading with humans and enjoys the privilege of sleeping in the farmhouse while the other animals sleep outside or in the barn. After the windmill is destroyed, the animals begin to starve as Napoleon enjoys a healthy, substantial diet and becomes more distant from everyone.
Napoleon further demonstrates his abuse of power by starving nine hens to death after they refuse to increase their required amount of eggs per week for trading purposes. Napoleon also awards himself “Animal Hero, First Class” and “Animal Hero, Second Class” and orchestrates a purge by publicly executing political dissidents. Conditions on the farm rapidly deteriorate and Napoleon continues to live a luxurious life while the other animals begin to starve or die of exhaustion. Overall, Napoleon abuses his power by enjoying special privileges while the other animals on the farm suffer and die.

Napoleon abuses all of the Seven Commandments of Animal Farm. He makes friends with humans, sleeps in a bed, wears clothes, get drunk, and harms rather than befriends the other animals. He has animals executed and establishes a hierarchy so that all the animals are not equal. The pigs and the dogs live very good and comfortable lives while the rest of the animals are kept hard at work and hungry.
Napoleon trains guard dogs to protect him and to attack and intimidate those who disagree with him. When the hens refuse to give up their eggs to be sold, staging a protest, he starves them until they comply.
One of Napoleon's worst abuses is not allowing the faithful Boxer to retire. Boxer always does more than his share of work without complaining and is always loyal to Napoleon. He has looked forward to a period of peace and rest at the end of his life. However, when he gets too old to work, Napoleon sells him to the glue factory.