Operations Manager, Jim Hurley, says the lizard either got loose while outdoors getting some exercise or the owner didn't want it anymore and set it free.
The 5' long lizard was first seen Tuesday afternoon. Hurley says the cold weather will eventually kill the lizard, but it can be dangerous if approached while it lives.
Janesville police say it's illegal to own an "exotic" pet in the city. The fine, if levied, is $389.50.