An unmistakable massive black cuckoo with creamy-white wing patches that are visible both perched and in flight. Rare pale forms also occur that have pale heads and variable buff areas on their bodies. Juveniles similar to typical dark adults, but show chestnut on the underparts. The species is found in pairs or small groups within dense tangles in the understory of forest and in nearby thick undergrowth. Often detected by call, a series of deep, very low-pitched “boop” notes, descending toward the end. Also gives a very different, harsh, scraping “chow” call in alarm.