Generally less than 80 cm (31 in) in length, its maximum reported length of 121.8 cm (48.0 in) was for a specimen in Florida (Niell, 1958) and 129.5 cm (51.0 in) (Roze, 1996). Males have longer tails than females, but females reach a greater total length.
The dorsal scales are smooth in 15 rows. The ventral scales number 197-217 in males and 219-233 in females. There are 40-47 subcaudals in males and 30-37 in females. The anal plate is divided.
The color pattern consists of a series of rings that encircle the body: wide red and black rings separated by narrow yellow rings. The head is black from the rostral to just behind the eyes. The red rings are usually speckled with black. People who live in its natural range are often taught a folk rhyme as children: "Red touches black, friend of Jack, red touches yellow, kill a fellow." The rhyme is useful in teaching children to distinguish king snakes (Lampropeltis ssp.), which are considered helpful predators of vermin such as rats and mice, from this much more dangerous snake that should only be handled by an experienced biologist or herpetologist. However, this rhyme is only applicable to the North American species, and cannot be used reliably in the Caribbean, or Central or South America.
Its common names include eastern coral snake, American cobra, candy stick, common coral snake, coral adder, Elaps harlequin snake, Florida coral snake, harlequin coral snake, North American coral snake, red bead snake, thunder-and-lightning snake, candy-stick snake, eastern coralsnake, Florida coralsnake, harlequin coralsnake, and serpiente-coralillo arlequÃn (Spanish).
