The lucifer sheartail or lucifer hummingbird (Calothorax lucifer) is a medium-sized, up to 10 cm long, green hummingbird with long decurved bill, small wings and white streak behind eye. The male has an iridescent plumage, forked dark tail, green crown, long magenta gorget and white underparts. The female is larger than male with duller plumage, pale throat and buff below.