The stygian owl (Asio stygius) is a medium-sized "typical owl" in subfamily Striginae. It is found in Mexico, parts of Central America, Cuba, Hispaniola, and 10 countries in South America.
The stygian owl is 38 to 46 cm (15 to 18 in) long and weighs about 400 to 675 g (14 to 24 oz). The sexes have similar very dark plumage. (The adjective "stygian" means "of, or relating to, the River Styx", but is more widely applied to anything that is dark or dismal.) The face is blackish with a pale border and a whitish forehead, and the head has long dark feathers that project upward as "ears".