Great Egret

35-41" (89-104 cm). W. 4'7" (1.4 m). A large, all-white heron with a yellow bill and black legs. In breeding plumage, has long lacy plumes on back. Much smaller Snowy Egret has black bill and legs and yellow feet. In southern Florida, white form of Great Blue Heron is similar but larger, with greenish-yellow legs.

http://birds.audubon.org/birds/great-egret