Adults are approximately 25 in long and weigh 28 oz. They have a black crown and back with the remainder of the body white or grey, red eyes, and short yellow legs. They have pale grey wings and white under parts. Their resting posture is normally somewhat hunched but when hunting they extend their necks and look more like other wading birds.
Fun Fact Scientists find it easy, if a bit smelly and messy, to study the diet of young Black-crowned Night-Herons—the nestlings often disgorge their stomach contents when approached.