A Great-billed Heron. Adults are 114 to 115 centimeters tall and their plumage is overall grey. It resembles the somewhat taller White-bellied Heron, but has a slightly brownish shine, a shorter neck, a less defined pale throat, and a dull greyish belly and vent.

Furthermore, the Great-billed Heron has yellow irises, grey legs and a dark grey bill, which is slightly pale-yellowish on the underside, near the base. Its facial skin is pale-yellowish to grey. In the breeding season, the plumes on the scapulars and are less dull.