The Greylag is the largest and bulkiest of the grey geese of the genus Anser. It has a rotund, bulky body, a thick and long neck, a large head and bill. It has pink legs and feet, and an orange or pink bill. It is 74 to 91 cm (29 to 36 in) long. It weighs 2.16 to 4.56 kg. The wingspan is 147 to 180 cm (58 to 71 in).Males are larger than females, with the sexual dimorphism more pronounced in the eastern nominate subspecies rubirostris. Their plumage is greyish-brown, with a darker head and paler belly with variable black spots. It has a white line bordering its upper flanks. Its coverts are lightly coloured. Juveniles differ in that they lack the black-speckled belly.

Calls and Songs

It has a loud cackling call, HOOOOOONK!, like the domestic goose.