With the Christmas season well and truly upon us, there's no end of festive puzzles sweeping the web.
However the latest eye-boggling brainteaser to leave the internet scratching their heads may just be the trickiest yet.
The Where's Wally-style quiz challenges users to spot the Father Christmas carrying a sack bursting with cash among a sea of Santas.
With over 160 to choose from, the figures are almost identical with matching hats and brown bags - except for their coats being different shades of red.
To make matters even more complicated, each bearded Santa is holding a sack overflowing with green presents - the exact same colour as the wad of cash.
However, eagle-eyed users have spotted that the Santa with the most dough is located towards the bottom right of the picture - third row up, third from the right.
The puzzle, created by Vouchercloud, is just the latest in a series of festive brainteasers to leave the internet bamboozled in recent weeks.
Yesterday, a spot-the-object puzzle from Playbuzz asked users to find the unique snowflake in a series of pictures.
It is said that no two snowflakes are the same - however, in these pictures all of them are identical bar one, but can you find the odd one out?
In each of the 12 images, spotting the snowflake proves fiendishly tricky as the subtle difference is often barely noticeable.
Some of the illustrations feature as few as six different flakes, with the larger graphics proving easier to spot.
However, the more snowflakes featured in the picture the trickier it becomes to seek out the odd one out.
In one image featuring 33 snowflakes, only the most eagle-eyed players will be able to spot the non-matching snowflake hidden among the flurry.
This is not the first festive puzzle to emerge this year with an eye-boggling Christmas brainteaser doing the rounds earlier this month.
In a group of reindeer users are asked to spot a little red-breasted robin perched on one of their backs.
He's sitting snug, staring straight at you while you're trying to figure out exactly where he is.
A recent brainteaser from Focus will really test your eyes and see whether you can see the difference between the robin and the reindeer.
The red noses of the reindeers camouflage the robin's red-breast perfectly.
There are a number of confusing elements to the puzzle, such as reindeers with patterned horns, red and yellow scarves and Santa hats which draw your eye away from the Robin.
Another seasonal brainteaser shows rows and rows of knitted jumpers, hats and scarves - but hidden between them is a bucket and spade, which internet users are struggling to spot.
The bucket and spade are exactly the same colour as the other items in the image, making them very tricky to find.
The company behind the puzzle, HolidayGems.co.uk, say the puzzle represents the winter sun you could enjoy if you're planning to jet off on holiday anytime soon.