Any of about 50 species of lizards (genus Varanus, family Varanidae) found in the Old World tropics and subtropics. Most have an elongated head and neck, a heavy body, a long tail, and well-developed legs. The smallest monitor grows to 8 in. (20 cm), but several species (e.g., the Komodo dragon) are very large. The two-banded, or water, monitor (V. salvator) of Southeast Asia grows to 9 ft (2.7 m). The perentie (V. giganteus) of Australia grows to 8 ft (2.4 m). The earless monitor (Lanthanotus borneensis), a rare lizard of Borneo and the only species of the family Lanthanotidae, grows to 16 in. (40 cm) in length.
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