The experts at www.BritanniaCoinCompany.com, who buy and sell collectible coins, have spotted a hidden image in the new range of King Charles III coins being released to the UK.
Many coins over the years have had quirky features. The £1 coin featuring The Queen, launched in 2017, featured a number of security features to prevent cloning, including an invisible binary code that was printed directly onto The Queen's face that is only detectable by the Royal Mint's counterfeit coin machines.
The Scottish £5 note, launched in 2016, features a very small midge, an infamous insect known for taking over the country, particularly the Scottish Highlands, in the spring and summer months.
In 2008, The Royal Mint released new coins designed by Matthew Dent which, when arranged together, create a royal shield of arms. You can see segments of the shield on UK 1ps, 2ps, 5ps, 10ps, 20ps and 50ps - a coinage Easter egg that often surprises international tourists.
On the US $1 bill, eagle-eyed people will spot Roman numerals at the bottom of the pyramid; these numbers refer to 1776, the year when the Second Continental Congress declared independence from Britain, forming the United States of America.
King Charles III has what appears to be a bird of some sort whispering into his ear.
Jon White, Director of www.BritanniaCoinCompany.com, said: "Once you've seen the bird on King Charles's ear, you'll zero-in on it every time you see one of his coins and I suspect you'll never un-see it.
"I have no idea if Martin Jennings, the artist, intended to include this hidden image. If he did, I think it's clever and fitting acknowledgement of His Majesty's passion for wildlife and that he's listening to the plights our natural world faces.
"These new coins already have collectors talking, thanks to the King's choice to be shown without a crown. Supposedly, he wanted to keep the design simple and without extra embellishment. Lots of these Charles III coins are already in circulation but they'll become more common as more are released, meaning everyone will get the chance to spot the secret bird detail for themselves."