The name and appearance of the Komodo dragon is straight out of legend. In reality these are huge, heavily-built monitor lizards - the biggest lizards in the world. The largest accurately recorded dragon was 3.1m long and a weighty 166kg. It was once thought that Komodos used deadly saliva containing toxic bacteria to poison their prey. Studies have now shown that they are venomous. Glands in the jaw secrete a complex mix of toxic substances into a wound made by the dragon's teeth. Komodo dragons are at the top of the food chain on their Indonesian island homes of Komodo, Rinca and Flores.