According to a Daily Star UK, some revellers were astounded after blue sea monsters invaded a series of beaches in Sydney.
The “blue-dragons” have overrun Sydney’s beaches after arriving out of the water on Freshwater and Curl Curl.
Experts have revealed that the alien-like creatures are in fact blue ocean slugs.
But any beachgoers looking to touch the beasts have been warned they give off a potentially dangerous sting.
Australian Museum’s Melissa Murray revealed that they were part of the blue bottle family.
She added: “They’re absolutely beautiful.
“The glaucus atlanticus normally has tentacles in is system.
“If another creature tries to eat it they use the tentacles as a defence mechanism.
“So if you do seen one, don’t pick it up with your hands. Use a bucket with water instead.”
Surfers down under were previously baffled when they spotted a mysterious sea creature.
A “half-shark, half-dolphin” caused surfers to swim for their lives in New South Wales.