Any of several slender, swift snakes (subspecies of Coluber constrictor, family Colubridae) of North and Central America and Asia. Racers have a long tail, big eyes, and smooth scales. Colour and pattern vary among subspecies, some of which grow to 6 ft (1.8 m) long. Among the fastest of snakes, racers can move at 3.5 mph (5.6 km/hr). They hold down their prey, usually a small warm-blooded animal, by the weight of their coils and then swallow it. If cornered, they vibrate the tail and strike repeatedly with a sideways motion that tears a victim's skin. See alsoblack snake.