EASTERN WATER DRAGON Physignathus lesueurii (Gray, 1831)
This 65 cm lizard lacks the blue and green colours found in the Gippsland Water Dragon Physignathus howittii.
Adult male Eastern Water Dragons instead have bright blood red bellies. Some males exceed 90 cm, and fighting between males during the breeding season is common.
Males appear to be territorial and all females within a given males territory are under his 'control'. Immature specimens are apparently not affected by the territorial behavior of adult males.
The Eastern Water dragon is found along the east coast from south of Sydney (NSW) to Cape York (QLD).
It is common for specimens to drop from a great height out of a tree and into a creek below when disturbed. These lizards are also known to inhabit rocky areas adjacent to beaches and also live around mangrove swamps. A preferred habitat of this lizard is areas infested with the introduced weed Lantana Lantana camara, which afford it impenetrable protection.
When running through Lantana Lantana camara this lizard makes a considerable noise rustling through the dead leaves and can be heard from quite a distance. An adaptable lizard, it is found on all shores of Sydney Harbour and is common in heavily built up areas. Its diet is mixed. The ten or so eggs are laid under cover in well-concealed locations, in summer which hatch about 80 days later. Young specimens lack bright adult colours.

The above was from the book Australian Reptiles and Frogs by Raymond Hoser and now available on a fantastic CD-Rom along with a vast amount of other information, papers and the like on reptiles, frogs and other wildlife.