The Giant Lizard is one of the mutant animals that was kept by Chu Sing Ling.
History: This monster was another creation of Chu Li Sing and was used to threaten Dr. Quest into cooperating with his weapons production plans for his bacteria and monsters. However, Race Bannon and Jade managed to reach the famous scientist and send the madman on the run to his henchmen. Before they could escape, both the Lizard and a Giant Spider used to threaten him were freed from their cages, but before they could get out and destroy the humans, they were crushed underneath the cement and metal of their enclosures, pushed upon them by the young Jonny Quest and Hadji riding a Bulldozer.
- The lizard was trapped by the ceiling parts when it was in its cage. It is unknown if it escaped after Chu Sing Ling was killed.
- There is another lizard that was mutated (by accident), but unlike the lizard that was kept by Chu Sing Ling, this lizard doesn't have spikes on its head, its claws are white, and it is much taller (approximately 120 ft.) than the one in the cage (which is about 8 ft. like the crab and spider).
- Its roars and growls resembles a crocodile's.