"No, Harry, dear, I'd much rather you helped Arthur muck out the chickens..."
--Molly Weasley (DH6)
The chicken is a common type of domesticated fowl. They were kept at the Burrow (CS3, DH6) and on the Hogwarts grounds (CS11). Chicken is mentioned several times as a food served at Hogwarts (PS7, CS5, GF27).
Although chickens themselves are non-magical creatures, they have special connections to Basilisks. A chicken egg will produce a basilisk if hatched under a toad (FB). When roosters were being killed at Hogwarts, Hagrid suspected that the culprit might be a blood-sucking bugbear (CS11). In reality, the chicken-killer was Ginny Weasley possessed by the spirit of Tom Riddle from his Horcrux diary. The chicken blood was used to write a warning to Muggleborns about the Chamber of Secrets on the wall at Hogwarts (CS9), but Tom’s spirit made Ginny kill chickens were killed because the crowing of a rooster could be fatal to a Basilisk (CS16).
Italian broom-racer Silvio Astolfi was transfigured into a chicken in the immediate aftermath of a neck-and-neck race ended in explosions and damage to the Roman Colosseum (BoS).
Hagrid fed baby Norbert a mixture of brandy and chicken blood (PS14).
When Harry went to Ministry of Magic headquarters for his hearing, a man named Bob was taking a fire-breathing (but otherwise seemingly normal) chicken to the Department for the Regulation and Control of Magical Creatures (OP7).