Kakapos are quite different from other parrots in terms of physical appearance. They are flightless and have a rotund, owl-like body shape, with a greenish-yellow plumage mottled with black and brown. They have a relatively short, curved beak and large, expressive eyes. They are also relatively large, weighing up to 4 kg (9 lbs) and standing about 60 cm (2 ft) tall.