These smooth scaled, glossy snakes are iridescent in appearance. The back is blue -black with three red stripes. The belly is red or pink with two or three rows of black spots with yellow margins. Adults average 68 - 122 cm (26.8 - 48 in) in total length. The record is 173 cm (68.1 in). Females are stouter and grow larger than do males. The Rainbow Snake has a sharp, pointed scale at the tip of its tail.
After breeding in early spring, a female Rainbow Snake lays 20 - 52 eggs in June or July. Eggs are buried 10 - 15 cm (3.9 - 5.9 in) deep in open sandy soils near water. The young hatch in August or September and may overwinter near the nest after hatching. Young move to aquatic environments the following spring.
The Rainbow Snake is an aquatic, burrowing snake, and is almost always found in or near water. It inhabits rivers, streams, cypress swamps, ponds, and marshes. It specializes on eating the American Eel Anguilla rostrata, which is how the Rainbow Snake got the nickname "Eel Moccasin." The diet of both adults and juveniles also includes frogs, tadpoles, salamanders, Amphiumas, and Sirens. The Eastern Kingsnake, skunks, raccoons, and otters will eat Rainbow Snakes and their eggs. The Rainbow Snake is active year round in aquatic habitats and hunts for food mostly at night. It will burrow into loose sandy soils. On warm rainy nights this species may be found crawling across roads near swamps or streams.
The Rainbow Snake is found along the Atlantic and Gulf Coastal Plains from Virginia to northern Florida and west to Mississippi.
The Rainbow Snake is probably common, but it is infrequently seen because of its burrowing and aquatic habits.
The Mud Snake lacks the three red stripes on the back and double row of black spots on the belly that are found on the Rainbow Snake.