Name calling is a technique used by propagandists in order to discredit someone, as well as to incite fear and prejudice against an adversary, thus bringing about conclusions and actions against the target of the name calling.
In George Orwell's Animal Farm, in Chapter 1, Old Major tells the animals,
"Man is the only real enemy we have. Remove Man from the scene, and the root cause of hunger and overwork is abolished for ever."
Later, in Chapter 3,the pigs refer to human beings as "worthless parasitical human beings."
Then, in Chapter 6 after Napoleon has usurped power and made the animals work harder and discontinued the Sunday meetings, his propagandist, Squealer, addresses the animals and places blame upon Snowball, whom Napoleon has run off from the farm. He blames the animals’ confusion in the matter of the new policies on lies circulated by Snowball. And, addressing the animals, Squealer uses name-calling,
..."Do you know the enemy who has come in the night and overthrown our windmill? SNOWBALL! ...in malignity, thinking to set back our plans and avenge himself for his ignominious expulsion, this traitor has himself crept her under cover of night and destroyed our work of nearly a year...."
Of course, as Napoleon becomes more despotic, as in Chapter 8, he justifies his actions of some of the animals who dissent murdered as "killing the traitors."
Snowball, of course, is most targeted for name-calling once he is driven off Animal Farm. Napoleon and Squealer demonize and blame him for everything, such that Snowball attains a degree of supernatural interference reminiscent of folktales:
Whenever anything went wrong it became usual to attribute it to Snowball. If a window was broken or a drain was blocked up, someone was certain to say that Snowball had come in the night and done it, and when the key of the store-shed was lost, the whole farm was convinced that Snowball had thrown it down the well. Curiously enough, they went on believing this even after the mislaid key was found under a sack of meal. The cows declared unanimously that Snowball crept into their stalls and milked them in their sleep. The rats, which had been troublesome that winter, were also said to be in league with Snowball.
It's interesting to note that other animals considered problems, such as the rats, are made guilty by association with Snowball's name.
Snowball's name is again repeatedly evoked during the show trials in which the dogs slaughter a number of animals who confess to crimes they all say were incited by Snowball. Four young pigs confess, as well as the three hens who had led the protest against giving up more eggs; a goose admits to theft and three sheep to two different crimes: one to urinating in the drinking pool and two to murdering an old ram. Though the animals are "shaken and miserable" over the carnage, the idea of Snowball's treachery diverts them from the barbarity of the animal slaughter they have just witnessed.
On the other side of the propaganda spectrum, while Snowball's name is demonized, Napoleon's is ever more exalted. He comes to be called not just Napoleon, but "our Leader, Comrade Napoleon" and "Father of All Animals, Terror of Mankind, Protector of the Sheep-fold, Ducklings' Friend, and the like." These names add a godlike aura that increases his stature and further distances him from the other animals.