Why you shouldn't touch the alien-like sea creatures on Sydney beaches

The identity of alien-like creatures that have washed up on Sydney beaches has been revealed by experts, and beachgoers have been warned not to touch them.

Miranda Atkinson, who's visiting Australia from Alaska, snapped photos of the weird, blue animals washed up on Freshwater beach in Sydney's north over the weekend.

The creatures were also been seen on neighbouring Curl Curl beach.

Ms Atkinson said they're "one of the coolest things" she's seen on her trip so far.

"I would've thought they were fake if there weren't so many," she told Yahoo7.

The blue dragons were found washed up on Freshwater Beach. Source: Miranda Atkinson

The creatures have been identified as glaucus atlanticus, also known as the blue dragon or the blue ocean slug.

Australian Museum's Melissa Murray explained the creatures belong to the "blue tide" group of animals which include blue bottles.

"There's about five different types of animals floating around with the wind," Ms Murray explained.

"They usually come in at this time of the year with the north-easterly winds, but die once they hit the shore. They're absolutely beautiful."

Hundreds of sea slugs on Freshwater Beach

Ms Murray said while the blue dragons are amazing to look at, it's probably best to observe but not touch because they care capable of stinging people.

"As part of this system, these creatures feed on each other," she said.

"So, the glaucus atlanticus normally has tentacles in its system. If another creature tries to eat it they use the tentacles as a defence mechanism.

"So if you do see one, don't pick it up with your hands. Use a bucket with water instead."

The creatures commonly blow onto the northern beaches over the summer. Source: Miranda Atkinson

It follows a disgusting discovery of maggots washing up on beaches in Sydney's north earlier this month.

A Surf Life Saving spokeswoman said it’s believed a bunch of seaweed littered with maggot eggs had washed up during high tide, allowing them to hatch around Bilgola, Newport and Dee Why beaches.

The rock pool at Bilgola was closed after the infested seaweed was also in there.