Allusion
Throughout the novel Squealer is highly skilled at making speeches to the animals. He is also one of the leaders of the farm. Under the rule of Napoleon, Squealer does things to manipulate the animals.
Squealer represents Vyacheslav Molotov who was Stalin's protégée and head of Communist propaganda. It is also possible that Squealer represents the Soviet Newspaper of Stalin's Era "Pravda". This paper was Stalin's key to propaganda in the communist times, and was very powerful to proletarians of the time (proletarians being Boxer, the horse)
Read more about this topic: Squealer (Animal Farm)