An American Corn Snake has been found in a backyard at Tahmoor.
The resident contacted the NSW Department of Primary Industries who sent a snake catcher out to pick it up.
The snakes are illegal to keep in Australia because they pose a significant threat to native animals aswell as spreading disease.
They have successfully bred in other parts of the world such as the Cayman and Virgin Islands and the Bahamas.
Wollondilly Council's Natural Resources Officer Alex Burgess says there's the possibility, there are other Corn snakes out there.
People who see any invasive species are being encouraged to contact the Department on 1800 680 244.
IMAGE CREDIT: Wollondilly Council