Man attacked by angry octopus in Australia's Geographe Bay

Lance Karlson was on holiday and walking along the beach in Geographe Bay, Western Australia when he came across a seemingly very irritated octopus.

Now footage of his aggressive encounter with the animal has gone viral, with his 30 second Instagram video receiving over 264,300 views. The video shows a large octopus swimming in shallow water before it jumps out and thrashes its tentacles at Karlson.

"The angriest octopus in Geographe Bay!" he wrote in the caption.

"After going after a seagull it then decided my daughter and I deserved a lashing! I later discovered its home among a crab graveyard, where it came after me again!

In the comments of the post, Instagram users from all over the world expressed their disbelief and shock at the video.

"I was already hesitant with sharks and saltwater crocs … I'm never going in the water again," wrote one user.

"Dude this is unbelievable. It really shows the cunning nature of how octopuses are. Predators of the sea. But odd how it thrashed at humans. Great science footage," shared another.

"Everything in Australia is dangerous," one commenter joked.

"Wow that's amazing how lucky to see one in such shallow waters never see anything like that in the UK."

Lance Karlson was attacked by a octopus while at a beach in Australia. Photo / Supplied

Speaking to 7 NEWS, Karlson said he was later attacked by the octopus when he went swimming. The novelist and geologist said he saw the creature swimming away from a bed of shells, however it then reappeared behind him and lashed him on the arm.

"I was only there for a few seconds looking at the shells when I was struck on the arm from behind," he said.

"My goggles fogged up and then I was struck again, this time of the neck.

"I quickly swam back to shore, around 25 metres away."

Although he said the string "wasn't particularly painful," they did leave red welts on his neck and upper back.

While vinegar would have reduced the sting, Karlson, a former lifesaver, didn't have any available and was forced to improvise with Coke.

"I didn't actually know if Coke would work, but given how acidic it is I decided it was worth trying," he said.

"Turns out it works."