The Snowy Egret of the Americas looks very similar to the Little Egret of Eurasia in size and plumage, including the incongruous yellow feet on black legs.
It has more yellow on its face than the Little Egret and has a feathery crest in breeding plumage rather than nape plumes.
My thanks to Alexandra Makhnina for the above photos of the Snowy Egret.
Another of the key differences sometimes visible is that the
Snowy Egret has a yellow line down the back of its black
legs (unlike the Little Egret).
Snowy Egret with Yellow-crowned Night Heron