Ernie is a Giant Chicken with whom Peter Griffin has had a long history of violence. He often shows up in the middle of a scene and interrupts Peter and the two engage in a long, drawn out fight won always by Peter, who then returns to the scene battered and bruised and picks up where he left off, not knowing that Ernie, seemingly dead, awakens and gets up after Peter leaves, foreshadowing another future fight. Each fight also leads to serious destruction of the environment around them and heavy casualties to bystanders. The whole feud begins with Ernie giving Peter an expired coupon, as revealed in "Da Boom". However, in "Meet the Quagmires", Griffin's meddling in his past allows him to accidentally punch Ernie while dancing at Enchantment Under The Sea, giving a new birth to the rivalry, and the new reason Ernie gives him the bad coupon, and 15 more years of balled up anger.
Peter no longer accepts coupons from any chickens after "the incident" with Ernie. During a flashback in the episode "Da Boom," the Chicken gave him a coupon, but the coupon was expired. Peter was therefore provoked to attack him. A prolonged fistfight ensued, taking the two combatants all over a downtown metropolis. It appeared that Peter had ultimately defeated the Chicken by slamming his head into a photocopier repeatedly, though the Chicken then did a sneak attack on Peter (just when he was explaining what exactly happened to shocked office workers), putting him in a half-nelson/chokehold, thus resulting in the both of them falling off the office building with Peter landing on him. He was not actually dead, though, as he opens his eye.
He returned to assault Peter when he was defending Quagmire in "Blind Ambition", the fight took place at a train station, a cruise ship, and finally an airport. But again, he was not actually dead, despite his head being chopped up by an airplane's propeller, spoofing the scene from Indiana Jones; his leg is shown moving into a fist. This fight also had the introduction of the chicken scream.
In "No Chris Left Behind", their fight took place from the Griffin house, the sewers, a subway, a building site, an airplane and the Ferris wheel. After this, the two have forgotten what they are fighting about. Ernie takes Peter out for dinner to make up for the fights over a silly little expired coupon. And he brings his wife, another chicken named Nicole. Peter and Ernie seemed to have resolved their differences, but the peace was fleeting; another fight ensues when both of them insist on footing the bill. Despite having his brains bashed in by a frying pot he was not actually dead, as he again opens his eye.
This is the first and only time in the series that the giant chicken is referred to by name, Ernie.
Ernie made a cameo appearance in "Meet the Quagmires" when he got punched by Peter Griffin at the Country Club by accident while Peter was dancing; Peter convinces Death to send him back in time and eventually fixes his mistakes while in the past when Lois Pewterschmidt accepts to marry him instead of Glenn Quagmire, as an altered timeline plays out. Peter then dances with her and accidentally punches Ernie, angering him, but he is stopped by his friend, who tells him not to get so angry, because he'll probably never see him again.
- Ernie is the most commonly recurring antagonist in the series.
- Ernie also appears in the Family Guy Video Game! and in Family Guy: Back to the Multiverse.
- Ernie's British counterpart from the "Family Guy Viewer Mail No. 2" segment "Chap of the Manor" is an English Pheasant. While setting up for Queen Elizabeth II's visit, he gets into a brief slap fight with Neville, the British Peter.
- In "Yug Ylimaf", Stewie notes that Ernie has a kid in his preschool.
- Ernie appears in the special opening of "Valentine's Day in Quahog".
- Peter's conflict with Ernie was referenced by a headless chicken in "Life of Brian". In the vet, Stewie mentions that they had to share an ambulance with a chicken, and when Peter asks the headless chicken why he isn't running around, the chicken angrily says to Peter, "Don't talk to me; you have a bad reputation in the chicken community."
- According to the DVD commentary for "The Simpsons Guy", Seth MacFarlane intended to have the fight in "Internal Affairs" result in Ernie's death, but Peter Shin convinced him to keep the character for inclusion in the planned Family Guy movie.
- FG203 "Da Boom"
- FG403 "Blind Ambition"
- FG516 "No Chris Left Behind"
- FG518 "Meet the Quagmires"
- FG709 "The Juice Is Loose"
- FG810 "Big Man on Hippocampus"
- FG813 "Go, Stewie, Go!"
- FG820 "Something, Something, Something, Dark Side" (as Boba Fett)
- FG908 "New Kidney in Town" (mentioned)
- FG913 "Trading Places"
- FG918 It's A Trap! (as Boba Fett)
- FG1023 "Internal Affairs"
- FG1104 "Yug Ylimaf"
- FG1112 "Valentine's Day in Quahog"