Giant monitor: in 1979 herpetologist Frank Gordon, doing field research in the Wattagan Mountains in New South Wales, Australia, saw a 'large log' scampering off, which appeared to be an enormous monitor lizard nearly 30 feet long. 固opFoto / Fortean Monitor lizards are the family Varanidae, a group of lizards which includes the largest living lizard, the Komodo Dragon. Varanidae contains only a single genus: Varanus. In Australia monitor lizards are known as goannas