Question: Squealer is a fictional character, a pig, in which author's book, "Animal Farm", in the book, he is described as merely a fat pig, but in the 1954 film, he is a pink pig, whereas in the 1999 film, Animal Farm, he is a Tamworth pig who wears a monocle? 

Context paragraphs:
Snowball (Animal Farm): Snowball is a character in George Orwell's "Animal Farm".  He is largely based on Leon Trotsky and describes how he led the opposition against Joseph Stalin (Napoleon), though he also includes elements of Vladimir Lenin.  He is shown as a pink pig on the movie poster for the 1999 film "Animal Farm", being voiced by Kelsey Grammer.

Animal Farm: Animal Farm is an allegorical novella by George Orwell, first published in England on 17 August 1945.  According to Orwell, the book reflects events leading up to the Russian Revolution of 1917 and then on into the Stalinist era of the Soviet Union.  Orwell, a democratic socialist, was a critic of Joseph Stalin and hostile to Moscow-directed Stalinism, an attitude that was critically shaped by his experiences during the Spanish Civil War.  The Soviet Union, he believed, had become a brutal dictatorship, built upon a cult of personality and enforced by a reign of terror.  In a letter to Yvonne Davet, Orwell described "Animal Farm" as a satirical tale against Stalin (""un conte satirique contre Staline""), and in his essay "Why I Write" (1946), wrote that "Animal Farm" was the first book in which he tried, with full consciousness of what he was doing, "to fuse political purpose and artistic purpose into one whole".

Harold Whitaker: Harold Jackson Whitaker (5 June 1920 – 26 December 2013) was a British animator, whose credits included "Animal Farm" in 1954 and "Heavy Metal" in 1981.  He first worked for Anson Dyer, before spending thirty years as an animator for Halas and Batchelor.  He made a comic strip adaptation of "Animal Farm" in 1954.

Mike Western: Mike Western (b. Southampton, 4 February 1925; d. 13 May 2008) was a British comics artist.  He worked as a clean-up artist for GB Animation after military service in the Second World War, and later at Halas and Batchelor on their 1954 film adaptation of "Animal Farm".  In the early 1950s he joined fellow former GB Animation artists Ron "Nobby" Clark and Eric Bradbury at Amalgamated Press, drawing adventure strips for "Knock-Out", including the western "Lucky Logan" and the aviation series "Johnnie Wingco".

Napoleon (Animal Farm): Our Leader, Comrade Napoleon, Father of All Animals, Terror of Mankind, Protector of the Sheep-fold, Ducklings' Friend is a fictional character and the main antagonist in George Orwell's "Animal Farm".  He is described as "a large, rather fierce-looking Berkshire boar" who is "not much of a talker" and has "a reputation for getting his own way".  While he is at first a common farm pig, he exiles Snowball, another pig, who is his rival for power, and then takes advantage of the animals' uprising against their masters to eventually become the tyrannical "President" of Animal Farm, which he turns into a dictatorship.  Napoleon's greatest crime, however, is his complete transformation into Mr. Jones (original owner of Animal Farm), although Napoleon is a much more harsh and stern master than Mr. Jones is made out to be.

Squealer (Animal Farm): Squealer is a fictional character, a pig, in George Orwell's "Animal Farm".  He plays the secondary antagonist to Napoleon, the pigs' leader.  He serves as Napoleon's second-in-command and the farm's minister of propaganda, and is described in the book to be an effective and very convincing orator.  In the book, he is described as merely a fat pig, but in the 1954 film, he is a pink pig, whereas in the 1999 film, he is a Tamworth pig who wears a monocle.

Animal Farm (1954 film): Animal Farm is a 1954 British-American adult animated comedy-drama film by Halas and Batchelor, based on the book "Animal Farm" by George Orwell.  It was the first British animated feature to be released ("Water for Firefighting" and "Handling Ships", two feature length wartime training films, were produced earlier, but did not receive a formal cinema release).  The US CIA paid for the filming, part of the American cultural offensive during the Cold War, and influenced how Orwell's ideas were to be presented.  The CIA initially funded Louis de Rochemont to begin work on a film version of Orwell's work and he hired Halas & Batchelor, an animation firm in London that had made propaganda films for the British government.

The Little Animal Farm: The Little Animal Farm (Italian: "La Piccola Fattoria degli Animali" ) is an Italian pig sanctuary located in Airasca, Piedmont.  Founded by Federica Trivelli in 2009, the site currently houses 20 pigs across four sties.

Snowball's Chance: Snowball's Chance, is a parody of George Orwell's "Animal Farm" written by John Reed, in which Snowball the pig returns to the Manor Farm after many years' absence, to install capitalism — which proves to have its own pitfalls.

Animal Farm (1999 film): Animal Farm is a made-for-TV film released in 1999 by Hallmark Films and broadcast on the American cable channel TNT.  It is an adaptation of the 1945 George Orwell novel of the same name.  The film tells the story of farm animals successfully revolting against their human owner, only to slide into a more brutal tyranny among themselves.  The film received mixed reviews when it was broadcast, with much criticism directed at its ending.

Supporting paragraphs: Squealer (Animal Farm) Animal Farm (1999 film)
Answer: George Orwell