A QR code grants a legend.
The mythical Pokémon Magearna has been released for Pokémon Sun and Moon, with no time limit for picking it up.
Using the game's QR Scanner application with the code below following the first credit roll will send Magearna to the antique store in the game's first city. It will come at level 50, and will hold a Bottle Cap item for Hyper Training.