Harmless · Popular pet · Native to Southeast Asia and southern China

Asian water dragon

Physignathus cocincinus

Also called the Chinese water dragon
Data updated November 2026

Asian water dragon resting on a branch above a stream, showing a bright green body and a long banded tail
Fig. 1 — Adult on a branch over water, its usual daytime perch.
Close view of an Asian water dragon head with a spiny crest along the neck
Fig. 2 — A crest of soft spines runs from the neck down the back.

At a glance

A large, bright green lizard of stream-side forests in mainland Southeast Asia and southern China. It spends the day on branches over water and drops in to swim away when disturbed. It is one of the most traded pet lizards in the world, and collection has made it a conservation concern in the wild.

01

Identification

Asian water dragons are long, slender-limbed lizards built for climbing and swimming. Adults are mostly bright to olive green, often with paler diagonal bands on the sides, and the long tail is flattened from side to side and ringed with green and dark brown bands. A crest of soft spines runs from the back of the head along the neck and back. Males are bigger than females, with larger heads, taller crests and brighter colors.

  1. 01Green body. Bright green to olive green, sometimes with a pale or yellowish throat.
  2. 02Banded, flattened tail. Much longer than the body and ringed with dark bands, used like a paddle when swimming.
  3. 03Spiny crest. A row of soft spines along the neck and back, tallest in adult males.

Commonly confused with

The Australian water dragon looks similar in shape, but it is grayer or browner rather than bright green, usually has a dark stripe behind the eye and is found only in eastern Australia.

02

Size

01 ft2 ft3 ft4 ft Typical adult male · about 30 in (77 cm)

Large males reach about 90 cm (36 in) in total length, with a body (snout to vent) of 17 to 25 cm; most of the rest is tail. Wild males in Vietnam average about 77 cm (30 in) overall. Females are clearly smaller, with a body of 16 to 20 cm, and weigh up to about 250 g against roughly 600 g for big males. Hatchlings have a body only about 4.5 to 5.3 cm long.

03

Range & habitat

Rocky forest stream in Southeast Asia with overhanging branches
Fig. 3 — Rocky streams through lowland evergreen forest are the typical habitat.

This species is native to southern China, Vietnam, Laos, Cambodia and Thailand; records from Myanmar are unconfirmed. It has been introduced to Hong Kong, Taiwan, peninsular Malaysia and Florida. It lives along the banks of rocky streams in lowland evergreen forest, roughly from 50 to 820 meters above sea level, and rarely moves far from water.

04

Diet & predators

Asian water dragons are omnivores that eat mostly invertebrates. Insect larvae, termites, ants, snails and spiders are common foods, and they also take fish, small mammals, birds and other reptiles when they can. Plants make up a small and variable share of the diet; studies disagree on how much.

Feeds on

  • Insects and their larvae
  • Termites and ants
  • Snails and spiders
  • Fish, small mammals and other reptiles

Preyed on by

  • People, who collect them for food and the pet trade
  • Natural predators are poorly documented
Termites on a piece of wood
Prey — termites and other insects.
Clear stream flowing over rocks in a tropical forest
Habitat — the dragon escapes into water when threatened.

05

Behavior & seasons

Asian water dragons are active by day and spend much of their time on branches and rocks overhanging water. When startled they drop into the stream and swim away, and they are strong swimmers. They are not social; in captivity they usually do best kept alone.

Young animals make up most of the wild populations that have been surveyed, and adults are relatively scarce, which researchers link to heavy collecting.

06

Reproduction

Asian water dragons lay eggs. Females bury clutches of about 5 to 16 eggs in sandy soil, and the eggs take about 60 to 100 days to hatch. Animals can mature in their first year, at a body length of about 15 to 17 cm. In captivity, females may lay more than one clutch a year, and one case of a female producing young without a male (parthenogenesis) was recorded in 2019.

07

Conservation

The species is assessed as Vulnerable globally and is considered Endangered in China and Thailand and Vulnerable in Vietnam’s national Red Data Book; Thailand has protected it by law since 1992. The main threat is harvest for the pet trade and for food, along with loss of forest and stream habitat. More than 1.4 million live animals were imported into the United States between 1999 and 2018, about 95 percent of them wild-caught and nearly all from Vietnam. In 2022 the European Union and Vietnam proposed listing the species in CITES Appendix II to regulate international trade.

08

In captivity

Asian water dragons are popular pets, but they are large, active climbers and need far more space than a beginner lizard. Many animals in the trade are still wild-caught; captive-bred dragons tend to settle and tame more easily. They are generally calm once settled, but they are not social and are usually kept alone.

  • Enclosure. Tall, well-ventilated and front-opening, with branches for climbing. Care guides suggest at least about 4 × 2 × 5 ft for an adult, and ReptiFiles recommends 6 × 3 × 6 ft or larger.
  • Water. A large, deep pool for swimming and soaking, kept clean.
  • Heat and light. A basking spot around 90–95°F (32–35°C), a cooler side of about 77–86°F (25–30°C) and nights not below about 75°F (24°C), plus a UVB tube on a 11–13 hour day.
  • Humidity. About 60–80% during the day, higher at night.
  • Food. Mainly insects such as crickets, roaches and worms, with some leafy greens and occasional fish or rodent treats.

See a reptile vet if your water dragon has sores on its snout from rubbing the enclosure walls, swollen limbs or jaw, trouble shedding, or loses weight while refusing food. More pet care guides

Keep reading

Sources

Data updated November 2026 · How we build these pages