From this story in the Miami Herald:
The Nile Monitor, a dragon look-a-like lizard that grows to more than seven feet in length, has been spotted in West Palm Beach and there are unconfirmed sightings of the lizards in Central Broward. The Florida Fish and Wildlife Commission wants residents to report the scary looking reptiles and stay far away from them. "The concern is that these critters cannot only be defensive when cornered, but they also threaten our native species and ecosystem," said Gabriella Ferraro, an FWC spokesperson. Nile monitors are native to Africa and generally are let go in the wild by pet owners who grow tired of them. They are gaining in Florida's subtropical climate and this is the time of year when they are most active. Wildlife officials fear the carnivorous, invasive species are spreading in the state's man-made canals.
"Normally, they're found near water and they're pretty good swimmers,'' Ferraro said. "This is a high-priority species for us," Scott Hardin, coordinator of the FWC's Exotic Species Coordination Section, said in a statement. "We plan to go after them aggressively to either try to eradicate them or suppress their numbers."_