Greater adjutants are large storks standing between 120 and 152 cm tall with a remarkable wingspan of up to 250 cm. They have a long, thick yellow bill that extends from a sparsely feathered head and neck, which range in color from yellow to pink. Their heads often have dark, scabby patches of dried blood and feature a large, inflatable gular pouch. The legs, naturally dark, often appear ashen due to frequent defecation. In flight, these birds can be identified by their white underwing feathers and their heron-like habit of retracting their necks. Their bodies are covered in a mix of white and gray feathers, with the plumage appearing darker during the non-breeding season. Juvenile greater adjutants look similar to adults but have duller feathers and more neck plumage. While their exact weight in the wild is not known, they are estimated to be the heaviest of all stork species.