A creepy photo of something lurking in a dark basement is causing more than a few people to jump out of their skin after being shared on Imgur.
The sinister black and white photo features a red circle and viewers are urged to zoom in on the photo to find out what's in it.
However, the image - which has been viewed more than 120,000 times - is leaving people baffled when they can't see anything untoward within the circle.
"I honestly can't see anything," LLQPM2 commented. "The resolution on the image is just blurry."
Gglower1 asked: "I double clicked and nothing happened, am I doing something wrong?" and Blackhawk777 wondered if anyone else could see a Mario Mushroom.
However, others admitted to feeling scared once they finally spotted what was wrong with the image.
"I'M BROWSING AT NIGHT GOD DAMN IT," SkellyMonster wrote, while Insertintellectualnamehere recalled: "First time my boyfriend showed me this, I was in McDonald's. I screamed and threw my fries in the face of the lady opposite us. Everyone laughed."
In fact, there is nothing troubling within the red circle, but if you look to the left of the photo you will see a creepy face peering around the corner.
Ghost42981 wrote "Took a moment, that's a good trick. I can appreciate a good diversionary scare!"
And Beefcat was not afraid to admit that he'd jumped once he spotted the scary face.
The optical illusion snap has been shared before but has recently resurfaced online.
And last week, a seemingly mundane photo of three women sitting on a park bench left people in a similar state of confusion.
At first glance the photo appears to show the trio pausing for a sit down during a sunny stroll.
But there's something wrong with the image that only become obvious on closer inspection.
The photo, which was originally shared on Imgur, has recently resurfaced online to cause confusion.
On close inspection, there appears to be no seat on the bench and the women are hovering mid air.
The most likely explanation is that the bench features smaller pull out seats or the seat panels are missing leaving them to sit on the fram of the bench.
The snap is the latest in a long line of optical illusion photos to leave people baffled.
A photo of a bed with a part of the duvet circled in red went viral this week - with many not realising that the picture is really an optical illusion.
Within the red ring there's a section of a white duvet covered in a black floral pattern, as well as part of the carpet.
However, people who have spotted the image - which has been shared on Reddit - are struggling to work out what the circle signifies.
The image was posted by Imgur user Idon'tevenknowwhat'sgoingon yesterday, and has received more than 63,500 views.
Optical illusions are increasingly popular online. At first glance the below picture looks like a regular selfie of a woman striking a seductive pose on her bed.
However, if you look closer you will see that something is not quite right with the black and white image.
The shot has been driving the web to distraction ever since it went viral, with puzzlers unable to figure out the oddity.
The image has recently resurfaced on Facebook after it first originated in 2003, when it was posted by Deviantart user Missmiserystock. It was titled 'Look-carefully'.
At closer inspection it is revealed that the woman actually has six fingers instead of five.
The subtle abnormality is likely to be a clever trick of Photoshop, designed to confuse.
One internet user, Bogina, wrote: "Hahaha thats insane it took me a while to catch it good job!" [sic]
But are your eyes sharp enough to solve this brain teaser driving the web crazy?
It is just the latest in a series of brain teasing images baffling the internet.
An image of a floral carpet, uploaded by Jeya May Cruz from Pasig, the Philippines, was shared nearly 16,000 times and reached 120,000 reactions.
Why? Because the photograph contains a camouflaged mobile phone that is devilishly hard to spot.
If you are struggling, the phone has a floral pattern which does not quite match the carpet.
Still confused? The device is just beside the right side table leg at the top of the photo.
It may seem a simple find, but it has left thousands bewildered.
Jeya captioned her image: "Since I can't sleep, let's play a game. Look for the cellphone."
She works as a sales representative at Dell, and studied Banking and Finance at Far Eastern University.
Sometimes the easiest-sounding brain teasers are the most difficult ones. And another puzzle to recently sweep the web certainly plays by those rules.
Created by a PlayBuzz user, this colour photo depicts a grey car seat with a mysterious object hidden on it for you to find.
At first, the secret object is impossible to find.
However, after a more detailed search you can spot a grey iPad lying flat on the back on the seat.
The iPad is well-camouflaged because it's the same colour as the seat, with similar markings.
At first, the secret object is impossible to find. However, after a more detailed search you can spot the grey device lying flat on the back of the seat.