A large, long-tailed bird of montane forest with a long, curved bill. Male is mainly black with some iridescence and very long tail. Female is brown above with barred belly, black face and bib. Male does an astonishing display, where two articulated fans are lifted above the head and the whole body is swayed up and down. Similar to Brown Sicklebill, but Black is usually found at lower elevations and has a black chest. Voice, two sets of explosive, hollow, double notes “wak-wak! wak-wak!”.