It took the mint 400 hours to create its “masterwork”, which has a denomination of £10,000.
The enormous coin has already been sold to an unnamed buyer.
The mint was unable to provide details of the sale, but said that a coin of that stature would be priced in the region of six figures.
The 20cm-wide coin was created by a team of master craftspeople at the Royal Mint, combining traditional skills with innovative technology.
Modern techniques were used at the start of the process, with engraving machines used to carefully cut the design on to the coin.
A master toolmaker then hand-worked the coin, removing any marks made by the cutting process, before four days of polishing. Finally, the coin was laser-frosted to texture the surface.
For those not able to afford the original, versions of the design are available in a range of finishes, with prices starting at £13 for a £5 denomination brilliant uncirculated coin.
The coin marks the conclusion of the Mint’s Queen’s Beasts commemorative coin collection. The series takes its inspiration from 10 stone statues that lined the Queen’s route to Westminster Abbey at her coronation in 1953.
Starting with the Lion of England in 2017, the collection has showcased the history and symbolism of each creature in turn.
The coin reunites all 10 beasts in one design, also including a lion, griffin, falcon, bull, yale, greyhound, dragon, unicorn and a horse.
Clare Maclennan, divisional director of commemorative coin at the Royal Mint, said: “We are delighted to unveil a Royal Mint first with the creation of the UK’s largest coin to celebrate the conclusion of our Queen’s Beasts commemorative coin collection. It is the latest in our Masterworks series, which offer unique works of art for collectors, exclusively from The Royal Mint.
“The Royal Mint’s Queen’s Beasts commemorative coin collection has grown in popularity since the first beast was introduced in 2017 and has become a firm favourite amongst coin collectors across the globe.
“This coin sets a new standard for minting – combining centuries old techniques with innovative technology to create a unique and beautiful work of art. It is the largest coin ever created by The Royal Mint, and is testament to the expertise, craftsmanship and skill of our team.”