Watch: Aussie man beaten up by 'angriest octopus' on beach

An Australian man's holiday swim has resulted in a painful whipping by what he calls the "angriest octopus". 

Video of the octopus lashing out at geologist and author Lance Karlson at a Western Australia beach has gone viral on Instagram

Karlson says he was about to take a dip near the resort he and his family were staying at in Geographe Bay, when he spotted what he thought was the tail of a stingray emerging from the water and striking a seagull.

Upon walking closer with his two-year-old daughter, he discovered it was an octopus, and took the video, which shows the animal in shallow water taking a sudden strike in his direction with its tentacles.

"The octopus lashed out at us, which was a real shock," Karlson told Reuters.

After heading back onto the shore he decided to return to the water again, popping on a pair of goggles to investigate a collection of crab shells. 

He soon felt a blow from behind: "my goggles became fogged, the water was suddenly murky and I remember being shocked and confused". 

The angry octopus had whacked his neck leaving visible, red, painful welts. 

Karlson ran back up to the shore looking for something to treat the stings. Since he didn't have any vinegar, his preferred treatment, he settled for a can of Coke, pouring it over the welts. 

"I didn’t actually know if Coke would work, but given how acidic it is I decided it was worth trying," he told 7News.

"Turns out it works." 

The footage Karlson posted with the comment: "The angriest octopus in Geographe Bay!" has been viewed more than 180,000 times. Despite the caption, he said he felt apprehension but no animosity toward the animal.

Instagram users were mesmerized by the video: "The coolest post I’ve looked at yet this morning!" 

"Is that type of octopus dangerous? Amazing video!"

While others took it as yet another reason to stay away from the ocean. 

"I was already hesitant with sharks and saltwater crocs... you have attacking octopus. I'm never going in the water again." 

"I can’t believe how strong and fast those tentacles whipped out of the water."

"I’m so curious what it’s thinking! They are so smart, so there must have been a reason it was so grumpy."

Karlson believes the seagull is what riled up the octopus. 

It's not the first time octopus have been found to attack. In December researchers labelled octopuses as the "bullies of the ocean" after observing them hitting fish for no reason other than "spite". 

They discovered octopuses enjoy taking aim at their fish buddies for seemingly no reason at all.