HippopoThames, a 21-metre-long wooden hippopotamus seen floating through central London on Wednesday, is the latest work by Dutch artist Florentijn Hofman, best known for his Rubber Duck installation that has bobbed in waterways around the world since 2007. 

Known for his playful, oversized installation art, the inspiration for Hofman's latest work came after the 37-year-old sculptor learned prehistoric hippopotamuses once called the Thames home. Its design, which required it to fit under several bridges and is reminiscent of a grinning cartoon character, came in a flash while Hofman was reading to his young daughter.