The peregrin is a crow-sized falcon, with a blue-grey back, barred white underparts, and a black head and "moustache". It can go at up to 322 km/h (200 mph) in a dive, which means it is the fastest animal in the world. As with other bird-eating raptors, the female is bigger than the male. There are 17–19 subspecies recorded, and each varies slightly in appearance and where they live. There is disagreement over whether the distinctive Barbary falcon is a subspecies of the Peregrine or just a different species.