In the Harry Potter series, the Weasley Family owl Errol, is a Great Grey Owl.
The Great Grey Owl (Strix nebulosa) is large grey to greyish brown owl with dense, fluffy plumage, long wings and tail, and a large head. Females are larger and heavier than males.
When ground is covered with snow, a Great Grey Owl can hunt by hearing alone and often plunges into the snow to capture small rodents moving underneath - as far down as 30 cm.
They have been known to drive off predators as large as Black Bears when defending their nests.
They have earned the title of 'bearded owl' due to the characteristic white moustache presents below the bill.
They have the largest facial disc of any raptor, helping to give them an amazing sense of hearing.