A solid gold version of the coin will also be hidden in one of 3,000 advent calendars available.

The Royal Mint says a coin with the Atlantic salmon and the King's portrait is now the rarest 50p.

There are thought to be about 50 in circulation, with even fewer made from nickel brass.

The coin is from a time when Scotland ruled parts of northern England, experts believe.

The main character of the sequel sharing her name will appear on several versions of the coin.

The coins celebrate the King's love of nature, with the reverse side featuring a pair of bees.

The Treasury has denied that coppers will be scrapped completely but none will be minted in 2024.

Check down the back of the sofa - more than £7bn in old UK bank notes has not been cashed in.