Chicken

Chickens are long-domesticated farm animals, and until relatively recently also used to entertain and encourage gambling in the form of cockfighting.

Background
In a world where chickens are apparently extinct, it seems some survived underground and lead short lives on the surface protected by the short-lived residents of the Hilltop Farm ruins. Miles was most likely the primary caretaker as the only one with farm experience.

Characteristics
Chickens are gregarious, domesticated fowl reared for meat and eggs. They are the most common and widespread domesticated animals whose ancestors were domesticated up to 8000 years ago for food and/or entertainment in the form of cockfighting.

Appearances
Actual chickens are referred to in Fallout 2, Fallout 3 as taste and Fallout Tactics in the form of graffiti. Others may be found but only as a means of calling someone afraid. Fallout 4's Far Harbor DLC is the only instance in the entire fallout universe to date that features live chickens.