The Great Egret is the largest of the Australian egrets.
Its overall plumage is white, and, for most of the year, when not breeding, the bill and facial skin are yellow. The feet are dark olive-grey or sooty black, as are the legs. During the breeding season, the bill turns mostly black and the facial skin becomes green. Also at this time, long hair-like feathers (nuptial plumes) hang across the lower back, and the legs become pinkish-yellow at the top.