Arnold Ziffel is a pig featured in Green Acres, an American situation comedy that originally aired on CBS from 1965 to 1971 and was produced by Filmways, Inc.. The show is premised on rural American humor and features Oliver Douglas and his wife Lisa as city-dwellers who move to the unfamiliar environment of Hooterville, a fictional farming community. Arnold is a pig of the Chester White breed, but he is treated as the "son" of Fred and Doris Ziffel, who don't have any human children. Everyone in Hooterville (besides Oliver Douglas) accepts this without question. Arnold was usually played by a female pig, even though he is a male character. Arnold's first appearance was in the second season Petticoat Junction episode "A Matter of Communication".
The humor that surrounds the character of Arnold comes from his human-like abilities and lifestyle, and from the way the people of Hooterville insist on thinking of him as a fellow human. They invite him to town meetings, they play checkers with him (and lose), and they speak English to him and can understand him when he speaks with pig squeals and grunts. New resident Oliver Douglas is the lone hold out. He tries to explain to people that Arnold is just a pig, but no one will listen to him. On the contrary, they are suspicious of Oliver, because of his inability to communicate with Arnold. This dynamic is part of a larger theme of Green Acres, that Oliver's sense of logic is meaningless in the Hooterville universe.
Arnold can do pretty much anything a human can. He can write his name and change channels on the television. He watches the CBS Evening News with Walter Cronkite to keep up with the issues. He signs checks and can adjust the TV antenna, and he is the smartest student at the local grade school. He carries his lunchbox in his mouth, and often plays practical jokes on the other students. Arnold is also artistically talented: he is working on a novel, he plays the piano, and he is an accomplished abstract painter, dubbed "Porky Picasso", whose piece titled "Nude at a Filling Station" wins first prize out of two thousand entries in a student art contest. He even works as a "paper pig" delivering newspapers, although he has a bad habit of throwing copies so hard and so badly aimed that he sometimes breaks windows.