This website documents the largest rice krispie square (technically a cube though) in CANADA. This man falsely claims to have the largest rice krispie square (actually a sort of cuboid, if you want to get precise) in Canada. I FOUND the photo of him below. Some ANONYMOUS individual on the internet drew a Charlie Chaplin moustache on his face. His claim is FALSE and also he is a journalist (opinion columnist apparently). This may seem like strong language, but a claim such as his can be quantified by numbers, and he refuses to provide PRECISE MEASUREMENTS . It is impossible to know if he ever really had the largest rice krispie square in Canada, but he definitely does not NOW. I think however that we are all used to deceptive claims in the media at this stage.
How's this for a FACT CHECK. I have made the LARGEST Rice Krispie Square (really it's an approximation of the platonic form of a cube) in Canada. My glorious creation is PRECISELY 18.5 x 18.5 x 18.5 inches. This is MUCH larger than Mr. Hopper's cube since volume grows at cubic rates. You may examine the photos below (which INCLUDE a RULER, like ANYONE who's actually INTERESTED in PROVING a size). As I consume my diabetic borg spaceship I shall update the photos for any haters.
The only possible way to fit all three Rice Krispies mascots in MISTER Hopper's so-called square would compromise the family friendly nature of Kellogg's long term advertising campaign and no doubt make Mr. Kellogg himself roll over in his grave given his well known puritan tendencies. Here is a rendering of the compromised position the elves would have to take to fit in that box of sin.
You have my permission, here's a tip though. Definitely don't use the Direkt spoon from IKEA to complete your cube. The lack of a silicone rubber handle or any other type of padding (wood, leather, even the cheapest of PLASTICS) means that your hand will be diREKT. I give it one star.