The character originated as an animated TV commercial for KGB-FM Radio in San Diego. Writer, cartoonist, and actor Brian Narelle, star of John Carpenter's film Dark Star, was working for Odyssey Productions and offered to animate a wacky acrobatic chicken as part of a commercial contract bid. Narelle went on to direct and animate the commercial as well as create cartoon art for the campaign.
In March 1974, Giannoulas was hired to wear the first suit. At the time he was a 20-year-old journalism major at San Diego State University. He was originally from Canada but had attended Hoover High School in San Diego. The Chicken's first appearance was a KGB promotion to distribute Easter eggs to children at the San Diego Zoo. Later the Chicken would wander throughout the stands at Padres games, and if someone said "Lay One On Me," the Chicken would "lay" an egg via his leggings containing a prize. A redesigned suit followed that more closely resembled The Famous Chicken today.
The Chicken, whose antics entertained steadily larger crowds, moved on to features at concerts and sporting events (appearing at more than 520 San Diego Padres games in a row), The Chicken also appeared at many San Diego Clippers games before the team relocated to Los Angeles. San Diego sports reporter Jack Murphy described him as an “embryonic Charlie Chaplin in chicken feathers”.
Conflict emerged between KGB Radio and Giannoulas, and the latter was fired on May 3, 1979. Another unnamed employee was hired to don a chicken outfit at a Padres game. Fans, many of whom were aware that Giannoulas was not in the outfit, booed the chicken loudly forcing him off the field. After a lawsuit was decided in Giannoulas's favor in June 1979 by Judge Raul Rosado, Giannoulas was allowed to continue to perform in a chicken costume (though not the same as the original costume). His self-styled Famous Chicken emerged from an egg at a "Grand Hatching" seen by 47,000 people at a Padres game at (then-called) Jack Murphy Stadium, as the sound system played the introduction to "Also sprach Zarathustra", the theme used in 2001: A Space Odyssey.
Beginning in 1981, Giannoulas co-starred on the Saturday morning children's television series The Baseball Bunch, alongside Johnny Bench and Tommy Lasorda. The Emmy Award winning series ran for five seasons and featured The Famous Chicken as the comic foil to Bench as he attempted to mentor a fictional baseball team of Little League aged children. In his 1984 review of the show, Miami Herald sports writer, Bob Rubin praised Giannoulas' contribution to the series writing, "The Chicken may be the most gifted physical comic since Curley, Larry and Moe."
In 1998, owners of the Barney the Dinosaur children's character sued Giannoulas for copyright and trademark infringement, over a sketch in which the Chicken engages in a slapstick dance contest against a Barney-like character. Giannoulas prevailed in the suit and recovered his attorneys' fees, based on the court's determination that his sketch was a lawful, legitimate parody.
The success of the Famous Chicken helped lead to mascots becoming widespread throughout professional sports, particularly Major League Baseball. The Chicken was named one of the 100 most powerful people in sports for the 20th century by The Sporting News. The pop culture publication 'Spy' referred to Giannoulas as the Laurence Olivier of sports mascots. He was inducted in the Baseball Reliquary Shrine of the Eternals.
Currently, the Chicken continues to make appearances annually across the United States. As of 2015 he is reported to have made 5,100 appearances in 917 different facilities, 50 states, and eight countries, wearing out more than 100 chicken suits.
- In 1975 The KGB Chicken made a promotional appearance at the first ComicCon convention. Convention organizers gave him the grand prize in their costume contest, then asked for it to be returned when they realized he was "a professional".
- Early in the first Holiday Bowl on December 22, 1978, uninformed security guards attempted to eject the Chicken from the field. He refused to leave the game, sitting on the sidelines as the mistake was ironed-out. Meanwhile, as Brigham Young University was working their way through the "red zone" for a touchdown the crowd was chanting, "We want the Chicken."
- The Chicken was on hand at Jack Murphy Stadium on September 10, 1978, when the Oakland Raiders beat the Chargers on the infamous "Holy Roller Play". After the Raiders recovered the winning touchdown in the end zone, the Chicken fell on the ground and lay motionless as though he had a heart attack.
- The Chicken appeared at WrestleMania XV and WrestleMania 2000, although the costume was worn by Pete Rose at WrestleMania XV during which he was 'Tombstoned' by WWE superstar Kane.
- The Chicken made a cameo appearance in the cult movie Attack of the Killer Tomatoes as one of the citizens stomping the remaining killer tomatoes in a parking lot.
- Giannoulas was once sued by the producers of the show Barney & Friends for beating up a Barney look-alike. The Chicken won the case, with the court holding that his performance was satire protected by the First Amendment.
- In 1979, the Chicken recorded a cover of Rod Stewart's disco hit "Da Ya Think I'm Sexy?"
- In the 1980s, the Chicken would appear in McDonald's commercials with Ronald McDonald. McDonald's founder Ray Kroc was also the owner of the Padres, at whose games the Chicken appeared frequently.
- The Chicken appears on a card in the 1982, 1983, and 1984 Donruss sets with an offer on the back of the card where you could send the card to The Chicken himself to autograph it.
- The Chicken is featured in the educational economics video, "Chickenomics".
- In 1994, the Chicken was featured in Boys Life magazine in a segment about mascots. Unlike other interviewed mascots who asked the magazine not to reveal their human names, Giannoulis was fine with his true name not being secret, and the article says that Giannoulis' antics helped set the standard as opposed to earlier dull mascots.
- In 2008, The Chicken was featured in a Sony commercial that also featured Dale Earnhardt Jr., James Brown, and Peyton Manning. In the commercial, The Chicken gets angry and is held back by Manning when a customer says he does not like sports.
- In 2013, a caricature of The Chicken was featured in a New Yorker cartoon by Paul Noth; Giannoulis commented "This means I've finally arrived!"