Jiri Lochman / Bungarra monitor lizard (Varanus panoptes subsp. panoptes) with tongue extended, Western Australia, Purnululu National Park UNESCO Natural World Heritage Site, Australia.

Jiri Lochman / Sand Monitor (Varanus gouldii), Cape Range National Park, Ningaloo Coast UNESCO Natural World Heritage Site, Western Australia.

Chris Mattison / Argus monitor (Varanus panoptes) flicking tongue, taken on white background, occurs in Australia and New Guinea

Martin Willis / Yellow-spotted Monitor (Varanus panoptes) sensing with tongue, Winton, Queensland, Australia

Martin Willis / Yellow-spotted Monitor (Varanus panoptes), Gibber Desert, Bedourie, Queensland, Australia

Martin Willis / Yellow-spotted Monitor (Varanus panoptes), Gibber Desert, Bedourie, Queensland, Australia

Miles Barton / Sir David Attenborough with Argus monitor (Varanus panoptes rubidus) standing on its hind legs when approached, Western Australia. November 2006, on location filming for BBC NHU series 'Life in Cold B...

Miles Barton / David Attenborough observing an Argus monitor lizard (Varanus panoptes rubidus) Western Australia, November 2006, on location for BBC NHU series 'Life in Cold Blood' This species of monitor rears up...

Miles Barton / David Attenborough observing an Argus monitor lizard (Varanus panoptes rubidus) Western Australia, November 2006, on location for BBC NHU series 'Life in Cold Blood' This species of monitor rears up...

Robert Valentic / Sand goanna standing threat display {Varanus panoptes panoptes} Queensland, Australia

Robert Valentic / Sand goanna standing threat display {Varanus panoptes rubidus} Western Australia

Bruce Thomson / Yellow-spotted monitor (Varanus panoptes) in sandy, arid habitat, Epping Forest National Park, Queensland, Australia.