Large, boldly patterned, long-tailed songbird of waterside areas, particularly fast-flowing streams but also rivers, pools, inland lakes, and coastal areas. Adult male velveteen black with white belly, wings, throat, brow, and outer tail feathers. Adult female similar but grayish black above. Juvenile similar, with soft, pale gray upperparts; juvenile of Japanese subspecies of White Wagtail similar but shows white arc behind eye. Calls distinctively buzzy.