Here are some watercolored sketches of a common flightless bird for a world I've been slowly forming in my head (let's call the bird a Domodon and the world Eternalfold...for now). I'll be slowly fleshing out the world with more paintings in the future as I figure things out. Keep in mind that nothing is final and these are all beta ideas. If you wanted to describe the world quickly I would simplify it as a vast fantasy realm of dragons, castles, demons, warring kingdoms and a touch of magic.
I have more info about them but since none of it is final and I doubt most will want to deal with an imposing wall of poorly written text I'll just outline some details here:
The Domodons live in large flocks that can roam 50 miles or more per day, living mostly on bugs, a bit of grass, and the occasional fruit. This is a male Domodon. The females have similar coloring but are a touch smaller and don't have the two blue tail fans, but they do have all the head plummage. The top right shows the peacock style fan tail that they use for threat displays and courtship. The running coal miner/chimney sweep fellow to the lower right should give you an idea of how large the average Domodon is compared to someone a little under 6 feet in height. Below that is what a flock would look like from a great distance in their typical environment. The main group mostly consists of the young, old, and the mothers while a smaller group of the fastest males forms a protective vanguard that circles the bulk of the flock, chasing off potential threats, scouting for water and keeping the slowest moving. The lower left shows how the Domodon sleeps by flipping the fan tail over the body to cover it. As well as visual camoflauge from the rock colored underside of the tail, the outer feathers are able to cool to the same temperature as the ground while hiding the bird's heat from the hungry nocturnal dragons that circle the desert (most of the time). Five ears on each side of the neck are protected by layered muscles and provide excellent hearing. Their feet have wiry hairs to pick up on ground vibrations and a long trenching claw for digging out grubs or disemboweling threats. Head bobbing and neck movements are very important for communication which is why they have those fuzzy blue puffs and head feathers that are so desirable to hunters. Their feathers are for temperature management rather than flight and so are more soft and fuzzy than the traditional wing feathers of birds that fly. The Domodon's eyes have 4 small pupils to reduce sun glare in the desert like a gecko although sight is a secondary sense to sound and smell.