The water dragon is a diurnal, semi-aquatic, arboreal, tropical lizard of Asia and Australia. The Asian water dragon (Physignathus cocincinus) is mainly green in color, with darker areas on the head and joints. The chin and throat are white to light yellow, and the underside is white to pale green.

The eastern water dragon (Physignathus lesueurii), from Australia, resembles the Asian water dragon in size and shape but is brown in color, with a gray to gray-brown underside. Broad black and narrow white crossbars run through the back and the tail of the animal. A prominent dark horizontal stripe may be visible on each side of the head, starting from the eye towards the neck. Like the Asian species, a dorsal crest runs from the head to the tail.

Water dragons do not have a dewlap, but instead possess large skin folds. A prominent dorsal crest runs from the neck to the tail. Juveniles are typically diagonally banded with 3 to 5 light stripes, usually pale blue to green in color, which disappear with age.

Water dragons live in humid, sub-tropical to tropical forests, tropical rain forest, wooded streams and rocky shores. Most adults usually reach 50 cm in length, (the tail counting for half to two-thirds of the length), but some can reach up to a meter in length. Longevity up to 11 years has been recorded.

Behavior

Water dragons are less aggressive and more placid than green iguanas, although are prone to intense spurts of speed. They are also smaller and therefore more manageable, but like most diurnal lizards they require a large spacious enclosure with high quality lighting and heating. All lizards can excrete Salmonella and therefore routine personal hygiene and the supervision of all child-water dragon interactions are important.

Water dragons are active but usually timid. They may attempt to flee when disturbed, often hitting their water bowl or the glass of the enclosure. Water dragons can sometimes be intolerant to other animals, so it is recommended to keep either a pair (male and female) or up to a male and two females together as a maximum in a single vivarium.