Robert Valentic / Heath Monitor (Varanus rosenbergi) male enacting a threat display, in mallee/heath habitat near Pinnaroo, South Australia.

Bruno D'Amicis / Desert monitor (Varanus griseus) moving across sand dunes, showing characteristic tracks, in the Sahara, Tunisia.

Jason Venus / Desert monitor {Varanus griseus} Sahara desert

Tony Heald / Southern savanna (Rock) monitor {Varanus albigularis} panting Etosha NP, Namibia

Steven David Miller / Perentie {Varanus giganteus} Northern Territory, Australia, Alice Springs Reptile Park - largest Australian monitor lizard

David Fleetham / Perentie (Varanus giganteus) walking across sand, Australia.

Daniel Heuclin / Desert monitor (Varanus griseus griseus) occurs in Sahara Desert. Controlled conditions.

Daniel Heuclin / Desert monitor (Varanus griseus griseus) occurs in Sahara Desert. Controlled conditions.

Daniel Heuclin / Desert monitor (Varanus griseus griseus) occurs in Sahara Desert. Controlled conditions.

Jiri Lochman / Ridge-tailed Monitor (Varanus acanthurus), Cape Range National Park, Ningaloo Coast UNESCO Natural World Heritage Site, Western Australia.

Jiri Lochman / Short-tailed Pygmy Monitor (Varanus brevicaudus), Cape Range National Park, Ningaloo Coast UNESCO Natural World Heritage Site, Western Australia.

Bruno D'Amicis / Desert monitor (Varanus griseus) moving across sand dunes, Sahara, Tunisia.