An extremely rare two-headed blue-tongue lizard has been handed to a NSW Central Coast reptile park by a member of the public.

Key points: The lizard has been named Lucky and is being cared for at the Australian Reptile Park

The lizard has been named Lucky and is being cared for at the Australian Reptile Park Staff say it is developing well and has two functioning mouths

Staff say it is developing well and has two functioning mouths Two-headed animals generally have a poor life expectancy in the wild

The lizard, which has since been named Lucky, had handlers at The Australian Reptile Park surprised and excited, with some experts predicting its life expectancy in the wild was not great.

Animals with this deformity often don't survive due to their eating difficulties and inability to defend themselves from predators, the park said.

Staff said the reptile was receiving the best care from experts at the park.

"Blue-tongues are such an iconic part of Australia and Lucky is one special little guy," head of reptiles Daniel Rumsey said.

Mr Rumsey said the park had seen the likes of two-headed snakes and sharks in the past.

Two-headed animals often don't survive in the wild. ( Supplied: Australian Reptile Park )

"We will treat him like the special little guy he is," he said.

These types of deformities are not completely unheard of and can occur when an incomplete embryo splits inside the egg.

Keepers are hopeful Lucky will live a long and happy life as perhaps the "most unique lizard in the entire wildlife sanctuary".

What to do if you come across a blue-tongue

Blue-tongue lizards are very common across the country and can usually be found in backyards feasting on snails in gardens.

When encountered, the lizards will expose their blue-tongue as a warning and could also turn towards the threat, hiss and flatten their body to make it look bigger.

Blue-tongue lizards are common in backyards across Australia. ( Supplied: Ashley Edwards )

If picked up, blue-tongue lizards have been known to bite when frightened.

Blue-tongue lizards are not poisonous and pose no risk to people or pets.

Experts say the best thing to do is make the place it has claimed as its home safe, by leaving some water and some rocks for shelter nearby.

Rescue groups such as the NSW Wildlife Information, Rescue and Education Service (WIRES) or The Australian Reptile Park can give advice on how to handle or care for an injured reptile.