From mythical creatures and prehistoric predators to Antarctic seabirds and war horses, fantastic beasts are popping up overnight on the region's popular tourist beaches. And there's one man who knows where to find them.

Carefully hand-crafted from bits of burned driftwood and grasses, these towering tributes to all creatures great and small - which have included a woolly mammoth, a dragon and most recently a two-metre high Adelie penguin - began appearing at different beaches in May - much to the joy and bemusement of locals.

That's when artist and screenwriter Peter Rush, who moved to the coast from Sydney six months ago, set to work on his guerrilla sculptures under the cover of darkness.

"I'd love to be totally Banksy but you can't get away with it. When I first started doing it at night people would turn up taking photographs," said Peter, in reference to the 'incognito' London-based street artist.

"I think the whole 'Banksy' thing is not knowing where they're going to turn up."

Except, unlike Banksy who tries to keep his identity under wraps, Peter likes to hang around once he's finished a piece, and is more than willing to chat with beachgoers about his work.

"I'm so happy for people. I made a little horse one day, and people on the beach called out and said it had made their day. I'm amazed. It's all about bringing a bit of joy in these COVID times."

In fact that was, in a serendipitous way, how it all started.

"I didn't imagine I'd be doing this when we moved up to Wamberal two months ago. No way in hell. I was painting landscapes and watercolours and then I decided to stop all that. I just knew something would come up. I waited. And this happened."

Peter has always been curious. As a kid in New Zealand, he remembers playing on the beach and finding the bones of the extinct giant moa bird. It was in May that he was at Terrigal lagoon when he spotted some driftwood that looked like a horse's tail and, as he puts it, he "had nothing to do". "I'm creative, I make things out of stuff, and I'm always thinking, always seeing things."

Then he found a bit that looked like a hind leg. He stuck the legs in the sand and from there "it was just a matter of tying on lighter sticks and building it up".

"People really got joy out of it in during the coronavirus pandemic, so I kept going."

Since then he's done around 15 sculptures including horses, a giraffe, an emu, a kangaroo, a pelican and huge Dromornis megafauna bird that needed a ladder to reach the top.

What is just as remarkable as how Peter makes such lifelike creatures out of bits of dead wood, is how he goes about it - armed only with a head torch, a Stanley knife and a handful of New Zealand flax from his garden which he uses like cable ties to join the pieces of wood together.

What he makes depends on what he finds on the beach that day.

"At Copacabana I did an almost lifesize mammoth. On the beach were these logs that just looked like knees of an elephant. So I put them in the ground to make an elephant. And then I noticed that this massive amount of dried brown weed. I thought this is more than an elephant, its a woolly mammoth."

He makes most of his sculptures at night, to minimise the amount of attention he gets while building them and so they are protected from any vandals.

"I have one little light on my head. It's amazing what you don't need, with starlight and moonlight. It's incredible, you've got the sound of the ocean, it's peaceful and you see shooting stars."

What also helps is Peter's background as an artist who used to draw storyboards for film and TV.

"It's essentially a driftwood drawing. So I get my phone and draw it until I can revolve it in my head. Then I can go and make it 3D."

He said as well as our deep psychological connection with animals, that grabs our attention, it's also practical to make a sculpture with legs that can be rooted in the sand.

"These things have to be 'off the deck' so having legs is a really big thing. I tried to do a seal once, which was a really big flop - literally. Legs are good."

Of course, with his sculptures being at the mercy of the elements - from wild winds and pounding surf to high tides - they are not designed to last forever.

It is this transience, he said, which is part of the appeal. "I had an emu here at Avoca Lagoon and after two weeks it wouldn't go away, it was so solid. So I took it down myself. It's like an exhibition - two weeks in a gallery is enough. And it's somebody's view. You turn up with this stuff, they might not like it. So give them their view back."

One of Peter's favourite creations was called A Hunch and Niggling Doubt which he built on MacMaster's Beach - two mythical creatures being riden by witch-like spirit figures. "I tell people: 'You've got a hunch I'm being sincere here, but there's a niggling doubt I'm taking the piss'."

Never one to rest on his laurels - "I don't like lazy people" - Peter's got two projects in the pipeline.

"Out in Avoca Lagoon I've got a huge Japanese snow monkey's head which I made with lantana 'hair' and I've got to retrieve. I was moving it into position and lost control of it and now it's sunk," he said.

"And on another beach I want to make a whale from 20 million years' in the future. This whale is coming back. He's realised the ocean's stuffed and there's nothing alive in there. All the food and vegetation is here on land. So it's evolved to come back on shore with legs and teeth."