The Mountain from Game of Thrones definitely won April Fools' Day

You might not recognise the name Hafþór Júlíus Björnsson (Thor, for short, because no one outside of Iceland knows how to say it), but anyone who has so much as blinked at a series of Game of Thrones will be familiar with his work.

Cast as Gregor 'The Mountain' Clegane from season three (Mark "Conan" Stevens got the gig for season one, while Ian Whyte was glimpsed in season two), Thor is also a professional strongman - coming second in the 2014 World's Strongest Man competition. He also broke an ancient Viking world record last year, for giggles.

You can now add "Top Prankster" to his bulging CV.

For reasons that are yet to become clear, the strongman has released an advert for his own brand of sparkling water, 'Heavy Bubbles'. Sure, it's an April Fools' joke, but we've no idea which brand has put him up to it. The accompanying website contains no information about the product, while the only small print in the advert is superbly mocking: Heavy Bubbles are very heavy. Please advise a family doctor before use. Don't believe everything on the internet.

We don't know why Thor has gone to the effort of making this, but we're glad he has.