The ridged-tailed monitor is a small monitor lizard related to the giant Komodo dragon of Indonesia and the perentie of the Australian deserts. Rarely longer than 700mm, it is an attractively marked lizard with light brown ocelli or 'eye spot' markings (round spots with a darker centre) on the upper side. The head is patterned with dark brown and cream stripes. The tail is the most distinctive feature with rows of rigid sharp spines forming ridges along its length. Monitors are the only lizards that, like snakes, have a forked tongue and this is constantly flicked in and out testing the air for different odours.