The Chocolate Orpington is a stunning, large, dual-purpose chicken known for its rich brown plumage, friendly temperament, and decent egg production, making it a popular backyard breed, though it's often a hatchery-created variety (a cross) rather than a standard breed, offering calm dispositions, cold hardiness, and lovely fluffy looks for homesteads, laying medium brown to cream eggs. 
Key Characteristics
Appearance: Deep, rich chocolate brown feathers, fluffy appearance, large body, red comb.
Temperament: Exceptionally docile, friendly, calm, and gentle, great for families.
Purpose: Dual-purpose (meat & eggs).
Egg Production: Fair layers, around 120-150 large, cream to light brown eggs per year.
Hardiness: Very cold hardy and heat tolerant.
Broodiness: Hens often go broody (want to sit on eggs).
Size: Large fowl, hens weigh 8-14 lbs, roosters 9-15 lbs. 
Origin & Status
While the standard Orpington is English, the Chocolate Orpington is often a specific cross developed by hatcheries (like Hoover's) using Chocolate and Black Orpingtons to achieve the color, making it a specialty, not an APA-recognized variety. 
Why People Love Them
Beauty: Their unique, deep chocolate color stands out.
Personality: Their calm nature makes them wonderful pets.
Fluffy: Like other Orpingtons, they have a fluffy, appealing look. 
In short, a Chocolate Orpington brings beauty, calm, and utility to a backyard flock, though they are a hatchery creation for that specific look.