THIS underwater brain-teaser has been puzzling puzzle fans for years.

The cartoonist Dudolf, otherwise known as Gergley Dudas, has drawn an ocean, filled with an array of colourful starfish, coral, seahorses, octopi, crabs and the like.

Amidst this paradisaical underwater scene, he has hidden a tiny fish for avid puzzle fans to find.

Hawk-eyed puzzle fans need to take in the whole picture, scanning the areas around the seaweed, sea-creatures and shells to find the fish.

Dudolf first shared the puzzle on his Facebook account on June 26, 2017.

His caption, reading “Can you find the FISH at the bottom of the ocean?” gave away nothing, and the cartoon continues to stump those that come across it.

The initial post has now been liked by more than 3,100 Facebook users, received 1,000 shares, and hundreds of comments from puzzled puzzlers challenging their friends and family to find the fish.

Facebook user Jessyca Hannah wrote: “This was harder than the others. Took me abit longer to find it”

And Sandi Batchelor said: “I found it on my own, but it took me forever!”

Read Related Also: Fan of the snooze button? Researchers say ‘there is no reason to stop’

While other social media users said that this was the easiest of Dudolf’s puzzles yet.

Aidni Molina said: The scenery looks amazing!!! This was a little easier for me this time. Thanks!”

And Jennifer Starrett said: “I found this one a lot quicker than your others. I love when new ones pop up on here!”

The cartoonist became an internet sensation after his drawing of a panda hidden amongst snowmen went viral in December 2015.

Dudolf has also released two books, Bear’s Merry Book of Hidden Things, and Bear’s Spooky Book of Hidden Things.

If you’re still struggling to find it, here’s a hint: look for a green fish in between the rock formations on the right hand side of the cartoon.

If you found this oceanic mystery a little too easy, we’ve also challenged our readers to tease their brain by finding the bat in this Halloween-themed puzzle.

Or, test both your vision and your IQ by trying to find the two cats hiding amongst the trees in this puzzle in under six seconds.

Although both are hiding in plain sight, one is far easier to spot than the other – and finding both is bound to stretch your brain.