Squealer is part of the trio of pigs who create the principles of Animalism, along with Napoleon and Snowball.
He is described as a “small fat pig [...] with very round cheeks, twinkling eyes, nimble movements and a shrill voice” (p. 9). We are also repeatedly told that is a brilliant talker, able to convince anyone of anything, as he can even “...turn black into white” (p. 9).
Throughout the story, Squealer plays the role of the pigs’ mouthpiece (especially Napoleon’s). Whenever the pigs do something that may be regarded as unfair or controversial, Squealer makes his rounds on the farm and tells various stories designed to convince the animals that the new rule is simply for the best for everyone.