The head is black with a narrow but obvious white supercilium, and it bears an inconspicuous crest of short stiff feathers on the forehead.

The mantle, neck and sides of breast are black which gradually blends into the dark purplish-blue of the rest of the plumage.

Outside the breeding season, larger groups of up to thirty may form, and they tend to roost communally, settling down for the night with much chatter.

[2] When foraging, they move methodically through the crowns of trees, searching in crevices and probing into mosses, lichens and other epiphytes.

[2] Cyanocorax argentigula is native to Costa Rica and Panama where it lives in moist cloud forest at altitudes between 2,000 and 3,200 m (6,600 and 10,500 ft).