Squealer is the pig that can convince anyone of anything. He is Napoleon's right hand man and carries out most of his dirty work.
"He was a brilliant talker, and when he was arguing some difficult point he had a way of skipping from side to side and whisking his tail which was somehow very persuasive". He can make people/animals side with him very easily.
Execution of animals
When napoleon executed the animals his goal was to instill fear in them and try to prevent them from rebelling against him as well.
Napoleons windmill was a symbol of animals accomplishing something without human.
Is the story Napoleon starts out like all the rest of the animals but after kicking snowball put and gaining power he begins to take on the habits of humans which were all the things animals were not to do. By the end napoleon had so much power he became more like a human than a pig.
Viva La Vida and the Message within the song: Power Corrupts
The video falls in with the theme of power corrupts and how Napoleon has become corrupt and now rules his once fellow comrades. ;)