<span lang="hi" dir="ltr">Erythrolamprus</span> ornatus, also known commonly as the ornate ground snake and the Saint Lucia racer, is a species of snake in the family Colubridae. The species is native to the eastern Caribbean. It is the rarest snake on earth with fewer than 20 left in the wild.
Erythrolamprus ornatus is endemic to Saint Lucia, an island nation in the West Indies, in the eastern Caribbean Sea. It once lived all over Saint Lucia, but now is only found on the islet of Maria Major.
Adults of this non-venomous snake, E. ornatus, may attain a total length (including tail) of . Its coloration is variable. Some individuals have a broad brown vertebral stripe. In others, the brown stripe is interrupted by alternating yellow spots.
The preferred natural habitats of E. ornatus are forest and shrubland, at altitudes from sea level to . E. ornatus is an ambush predator of small rodents and lizards, and probably diurnal. E. ornatus is oviparous.
In 1936, E. ornatus was declared extinct, but it was rediscovered in 1973. It disappeared again soon after, but 11 individuals were found in 2012 on the mongoose-free island of Maria Major off the coast of Vieux Fort, Saint Lucia. Currently the Durrell Wildlife Conservation Trust, working with Fauna & Flora International, Saint Lucia National Trust and Saint Lucia Forestry Department, are working to build a captive breeding population with two facilities, one for breeding the snakes and one for cultivating food sources.