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.
The lucifer sheartail is distributed to deserts and arid areas with agave plants in the southwestern United States, from southwest Texas, extreme southwestern New Mexico to extreme southeastern Arizona, and in central and north Mexico. It is also found in the Madrean sky islands of the northern end of the Sierra Madre Occidental, Mexico.
A locally common species in its range, the lucifer sheartail is evaluated as Least Concern on the IUCN Red List of Threatened Species.