Australian backyards play host to a wide variety of wildlife but one NSW resident had a snappy surprise when he spotted a crocodile.

The juvenile freshwater croc appeared on Sunday in the backyard of a home in Umina on the Central Coast, about 2500 kilometres south from where the cold-blooded reptiles are usually found.

The man contacted the nearby Australian Reptile Park, which dispatched handlers and keepers to trap the interloper.

Veteran crocodile keeper Billy Collett said he was “incredibly shocked” when he got the call.

“I honestly had to see it with my own eyes before I could believe it,” he told AAP.

The female croc is about one metre long and likely about eight to 10 years old.

While freshwater crocs are less dangerous than their saltwater cousins, they still present a risk to the community if one gets loose.

“They are still wild animals and can be unpredictable. It’s always best to leave them to the experts,” Mr Collett said.

The crocodile will undergo health checks at the park but Mr Collett said she is in good health, a healthy weight and has only a few scratches.

She was likely an illegal pet that was abandoned, considering how far she was from her natural habitat.

“We want to remind the public that keeping wild animals as pets is illegal and dangerous without a licence,” he said.

Sometimes people keep a baby crocodile as a pet, but panic when its size increases, prompting them to turf them out into the world … often into storm drains.

The crocodile’s owner is being asked to come forward as it spends a few days at the reptile park for health checks.

National Parks and Wildlife has been contacted and will decide her final destination.