Whilst acknowledging that it is a limiting interpretation, seeing the animals as representative of characters in the modern history of the Russian nation is the most obvious reading of Animal Farm. The following associations can be made:
Napoleon = Stalin or Lenin (also Napoleon Bonepart)
Snowball = Trotsky
Squealer = Party members who persuade the people of the Party's concern for them and correct judgement
Moses = Orthodox Church
Boxer and Clover = the proletariat who support the revolution
Benjamin = the proletariat who are untouched by the revolution due to their poverty and entrenched ideas
Pigeons = Soviets who passed the message of Communism beyond the borders of the Union
Old Major = Marx
Mr Jones = Tsar Nicholas
Mr Pilkington = the louche European allies
Frederick = Germany
Whymper = Capitalists who trade with Communist states
Mollie = White Russians
Dogs = KGB or NKVD - Communist Secret Police