The moonwing is a large avian creature originally derived from swans and taking its name from the sharp blades adorning its forelimbs. The blades are the creature's primary weapon, used to intimidate predators and rivals. The leading edge of these blades grows constantly to maintain its sharpness, and must be sharpened on a regular basis, meaning that a moonwing's territory can easily be spotted by the marks left on boulders and tree bark. The blades fold away when not in use into a matching groove on the underside of the forearm. They stand about as tall as a man, most of which is neck and leg. Males sport characteristic crests and a purple stripe down the back, while female plumage is plain white and less flamboyant.
Unlike its natural relatives, the moonwing is not aquatic and prefers grassland and open woods where it can freely graze and run. It is semi-social, lacking a strong herd/flock instinct, but tolerating others of its kind. It is a common sight to see two or three individuals keeping watch whilst their companions graze. Flocks will lay their eggs in a small number of communal nests and raise the cygnets as a group. Both male and female moonwings have been sighted guarding multiple young, many of which may not even be directly related to them.
Although they tolerate other moonwings, they do not extend this courtesy to anything they consider a threat, including people. Moonwings are known for being highly territorial, especially when guarding young, and will not hesitate to rush into a fight if threat displays aren't enough. Unlike natural birds, their bones are solid, allowing them more durability than normal - moonwings have a reputation for being exceedingly tenacious fighters no matter how outnumbered or outmatched. "You fight like a moonwing" is a well known phrase, although whether it's a compliment to one who won't give up despite poor odds, or a mocking comment toward someone who doesn't know when to quit, is dependent on the context.
Rumours exist of a variant of the species found in southern climates with black plumage and warm-coloured markings. These have been colloquially dubbed "Sunwings".