The Great Grey Owl is a very large owl, distributed across the Northern Hemisphere. Adults have a big, rounded head with a grey face and yellow eyes with darker circles around them. The underparts are light with dark streaks; the upper parts are grey with pale bars. This owl does not have ear tufts and has the largest facial disc of any raptor. In terms of length, the Great Grey Owl is believed to exceed the Eurasian Eagle-Owl and the Blakiston's Fish Owl as the world's largest owl.