Answer:
Squealer is a porker who was let into Napoleon's inner circle because of his ability to persuade the masses. 'The others said of Squealer that he could turn black into white.' When Napoleon needs to calm the other animals after an injustice is served, he sends Squealer. One of Squealer's preferred methods of gaining compliance is to inspire fear that if things aren't done Napoleon's way, Mr. Jones might come back, saying 'surely there is no one among you who wants to see Jones come back?' The threat of Mr. Jones returning convinced the animals to agree to the following. :)