black snake with red belly and yellow ring around neck
Ring-necked snake Its dorsal coloration is solid olive, brown, bluish-gray to black, broken only by a distinct yellow, red, or yellow-orange neck band.[6][7] A few populations in New Mexico, Utah, and other distinct locations do not have the distinctive neck band.[6] Additionally, individuals may have reduced or partially colored neck bands that are hard to distinguish; coloration may also be more of a cream color rather than bright orange or red.[7] Head coloration tends to be slightly darker than the rest of the body, with tendencies to be blacker than grey or olive.[7] Ventrally, the snakes exhibit a yellow-orange to red coloration broken by crescent-shaped black spots along the margins.[6] Some individuals lack the distinct ventral coloration, but typically retain the black spotting.[7] Rarely, do individuals lack both the ventral and neck band coloration; so the use of those two characteristics is the simplest way to distinguish the species.[6]
Yellow-bellied sea snake Hydrophis platurus, commonly known as the yellow-bellied sea snake, yellowbelly sea snake or pelagic sea snake, is a species of snake from the subfamily Hydrophiinae (the sea snakes) found in tropical oceanic waters around the world, excluding the Atlantic Ocean. It was the only member of the genus Pelamis but recent molecular evidence suggests that it is more closely related to the species of the genus Hydrophis.