This list includes 26 Reptiles that start with O, from “O’Shaughnessy’s Anole” to “Ouachita Map Turtle”. These reptiles span small arboreal lizards to large freshwater turtles and serve identification, study, pet care, and conservation needs.
Reptiles that start with O are species whose common names begin with the letter “O”. They occur worldwide, from tropical forests to rivers, and include familiar examples like O’Shaughnessy’s Anole.
Below you’ll find the table with Common name, Scientific name, Habitat, and Average size (cm).
Common name: The widely used name helps you quickly recognize species in field guides, labels, and casual reference.
Scientific name: Latin binomial gives you the exact species identity and links to formal literature and conservation listings.
Habitat: Brief description of typical environments helps you understand where to find or observe each species in nature.
Average size (cm): Mean adult measurement in centimeters shows relative size and notes the measurement type, like SVL or total length.
Reptiles that start with O
| Common name | Scientific name | Habitat | Average adult size (cm) |
|---|---|---|---|
| Ocellated Skink | Chalcides ocellatus | Arid, sandy, or rocky areas with sparse vegetation. | 20 cm (TL) |
| Olive Ridley Sea Turtle | Lepidochelys olivacea | Tropical and subtropical coastal bays, estuaries, and open ocean. | 70 cm (CL) |
| Ornate Box Turtle | Terrapene ornata | Prairies, grasslands, and open woodlands of the central United States. | 14 cm (CL) |
| Oriental Garden Lizard | Calotes versicolor | Gardens, agricultural lands, open forests, and urban areas. | 37 cm (TL) |
| Ouachita Map Turtle | Graptemys ouachitensis | Rivers and large streams with moderate currents and basking sites. | 12–25 cm (CL) |
| Olive Sea Snake | Aipysurus laevis | Coral reefs and shallow coastal waters in the Indo-Pacific. | 100 cm (TL) |
| Ornate Flying Snake | Chrysopelea ornata | Tropical forests, coconut plantations, and gardens in South and Southeast Asia. | 130 cm (TL) |
| Orinoco Crocodile | Crocodylus intermedius | Freshwater rivers and wetlands of the Orinoco River basin, South America. | 410 cm (TL) |
| Ocellated Lizard | Timon lepidus | Open woodland, scrubland, and olive groves in Southwestern Europe. | 60 cm (TL) |
| Oriental Whipsnake | Ahaetulla prasina | Forests, plantations, and gardens from lowlands to mountains across Southeast Asia. | 180 cm (TL) |
| Olive Python | Liasis olivaceus | Rocky escarpments, gorges, and coastal forests of northern Australia. | 250 cm (TL) |
| Ornate Tree Lizard | Urosaurus ornatus | River corridors, rocky canyons, and oak-juniper woodlands in the US Southwest. | 5 cm (SVL) |
| Ocellated Day Gecko | Phelsuma ocellata | Rocky outcrops and arid scrubland in Namibia and South Africa. | 10 cm (TL) |
| Orange-throated Whiptail | Aspidoscelis hyperythra | Chaparral, coastal sage scrub, and open woodlands in California and Baja California. | 7 cm (SVL) |
| Okinawa Habu | Protobothrops flavoviridis | Forests, grasslands, and agricultural fields on the Ryukyu Islands of Japan. | 150 cm (TL) |
| Ornate Day Gecko | Phelsuma ornata | Coastal forests and human-modified habitats on Mauritius and surrounding islands. | 12 cm (TL) |
| Ocellated Carpet Viper | Echis ocellatus | Savannas and grasslands of West and Central Africa. | 45 cm (TL) |
| Orange-naped Snake | Furina ornata | Savanna woodlands, scrublands, and rocky areas across northern Australia. | 40 cm (TL) |
| Olive House Snake | Lycodonomorphus inornatus | Grassland, savanna, and forests, often near water sources in southern Africa. | 75 cm (TL) |
| O‘Shaughnessy’s Anole | Anolis oshaughnessyi | Montane cloud forests in the Andes of Ecuador and Colombia. | 10 cm (SVL) |
| Ornate Black-tailed Rattlesnake | Crotalus ornatus | Rocky mountainous areas and canyons in the US Southwest and Mexico. | 90 cm (TL) |
| Ornate Spiny Lizard | Sceloporus ornatus | Arid, rocky habitats, including limestone cliffs and desert mountains in Mexico. | 9 cm (SVL) |
| Ocellated Shieldtail Snake | Uropeltis ocellata | Moist, high-elevation forests of the Western Ghats in India. | 40 cm (TL) |
| Olive Keelback | Atretium schistosum | Slow-moving freshwater bodies like ponds, streams, and rice paddies in South Asia. | 60 cm (TL) |
| Oaxacan Spiny-tailed Iguana | Ctenosaura oaxacana | Arid tropical scrub forest in southern Mexico. | 30 cm (SVL) |
| Otago Skink | Oligosoma otagense | Large rock outcrops (tors) in the tussock grasslands of Otago, New Zealand. | 14 cm (SVL) |
Descriptions
Ocellated Skink
A smooth, shiny skink from southern Europe to the Middle East. It is recognized by its small, scattered, eye-like spots (ocelli) and often “swims” through loose sand to escape predators.
Olive Ridley Sea Turtle
The most abundant sea turtle, famous for synchronized mass nesting events called “arribadas.” It has an olive-green, heart-shaped carapace and is found in the Pacific, Indian, and Atlantic Oceans.
Ornate Box Turtle
A terrestrial turtle with a high-domed shell marked with radiating yellow lines. Its hinged plastron allows it to completely close its shell for protection from predators. Primarily a prairie species.
Oriental Garden Lizard
A common agamid lizard in Asia. Males develop a bright red throat during breeding season, earning it the name “bloodsucker,” though it doesn’t drink blood. It’s an adaptable, insectivorous species.
Ouachita Map Turtle
Native to the Mississippi River basin. Identified by a prominent yellow rectangular patch behind its eye and a serrated keel along its carapace. Females grow significantly larger than males.
Olive Sea Snake
A highly venomous but generally non-aggressive sea snake. It’s uniformly olive-brown or yellowish. Unlike many sea snakes, it can move on land, though clumsily, and feeds on fish and crustaceans.
Ornate Flying Snake
A mildly venomous snake that glides from tree to tree by flattening its body and making serpentine motions. It is a skilled climber and an arboreal predator of lizards, birds, and bats.
Orinoco Crocodile
One of the world’s largest crocodilians, now critically endangered due to historical overhunting for its hide. It has a relatively long, narrow snout compared to the American crocodile.
Ocellated Lizard
Europe’s largest lizard, a powerful predator of insects, small reptiles, and even young mammals. Named for the blue, eye-like spots (ocelli) on its flanks. Its body is green with black patterning.
Oriental Whipsnake
An extremely slender, arboreal snake. Typically bright green, it has horizontal pupils, providing excellent binocular vision for hunting lizards and frogs. It is mildly venomous.
Olive Python
A large, non-venomous python known for its iridescent, uniform olive-brown scales. It is a powerful constrictor that preys on mammals, birds, and other reptiles, often ambushing them near water sources.
Ornate Tree Lizard
A small, fast-moving lizard often seen on tree trunks and rocks. Males have bright blue or blue-green belly patches and an orange or yellow throat, used in territorial displays.
Ocellated Day Gecko
One of the few day geckos adapted to arid conditions. It has a distinctive dark-ringed “eyespot” or ocellus on its flank, which is used to startle potential predators.
Orange-throated Whiptail
A fast-moving lizard with distinct longitudinal stripes and a vibrant orange throat, especially in males during breeding season. It actively forages for termites and other small insects during the day.
Okinawa Habu
A large, highly venomous pit viper endemic to Japan’s Ryukyu Islands. It is a medically significant snake with a bold pattern of dark green blotches on a yellowish-brown background.
Ornate Day Gecko
A small, brightly colored gecko with intricate red, blue, and black markings on a green back. Like other day geckos, it is active during the day and feeds on nectar and insects.
Ocellated Carpet Viper
A medically significant venomous snake responsible for many snakebites in its range. Its pattern of light, dark-edged “eyespots” provides camouflage. It creates a rasping sound by rubbing its scales together.
Orange-naped Snake
A small, nocturnal, venomous snake. It has a distinctive orange or yellow patch on its neck, which may serve as a warning display. It feeds primarily on skinks and other small lizards.
Olive House Snake
A non-venomous, uniformly olive-brown to black snake. Known for its placid temperament, it is popular in the pet trade. It often inhabits human dwellings, where it preys on rodents and lizards.
O‘Shaughnessy’s Anole
A large, robust anole from high-elevation Andean forests. It is typically green to brown with a distinct pattern. Males display a large, colorful dewlap to communicate with rivals and mates.
Ornate Black-tailed Rattlesnake
A venomous pit viper with a pattern of dark, well-defined blotches. Recently recognized as a distinct species from the Black-tailed Rattlesnake, it relies on camouflage among rocks and leaf litter.
Ornate Spiny Lizard
A medium-sized lizard with very keeled scales, giving it a spiny appearance. Males are colorful, with blue belly patches and a distinctive pattern of two light stripes on their back.
Ocellated Shieldtail Snake
A burrowing snake with a smooth, cylindrical body and a blunt tail ending in a rough shield. It is named for the yellow, black-edged ocelli (eyespots) along its body.
Olive Keelback
A non-venomous, aquatic snake with strongly keeled scales, giving it a rough texture. It is typically olive-green and preys on frogs, tadpoles, and fish in its freshwater habitat.
Oaxacan Spiny-tailed Iguana
A critically endangered iguana found only in a small region of Oaxaca, Mexico. It is threatened by severe habitat loss and illegal collection for the pet trade and local consumption.
Otago Skink
A large, long-lived skink that is critically endangered. It has a striking pattern of black, yellow, and green blotches. Conservation efforts include predator-proof fences and captive breeding programs.