The crested argus, genus Rheinardia, is a large and spectacular peafowl-like genus of bird in the pheasant family with dark-brown-spotted black and buff plumage, a heavy pink bill, brown irises and blue skin around the eyes. The head has two crests; the hind crest, which extends down the occiput, is erected when alarmed and during intentional behaviors including pair bonding and courtship displays. The male has a broad and greatly elongated tail of twelve feathers. The tail covert (or "train") of the male is the longest of any bird and is believed to contain the longest (and widest) feathers to occur in a wild bird; the Reeves's pheasant has tail feathers of similar length but which are considerably narrower. The tail coverts measure up to 1.73 m (5.7 ft) in length, giving the bird a total length of 1.9–2.39 m (6.2–7.8 ft).
From limited anecdotal observations of local indigenous peoples, both species select nest sites in elevated reaches, often amongst escarpments on steep slopes amongst leaf litter. They produce very small clutches of from one-two large eggs which are incubated for 25 days. Like other peafowls, crested argus chicks hatch with developed wing feathers. They are bill fed for the first few weeks. In captivity, males also invest in chick rearing, both bill feeding and brooding the chicks both on and off the ground.
Like other peafowl, crested argus retire on emergent trees above the forest canopy for many hours a day. They will remain on these trees for days at a time during the wet season. Crested argus are strong fliers and pairs have been reported flying together.