http://www.nintendolife.com/news/2014/06/mario_kart_8_toys_boosting_into_mcdonalds_happy_meals
Redbull has an interesting article on the history of the video game cheat code. Some of this information is well known and some isn't but it's still neat to see it laid out well.
http://www.redbull.com/en/games/stories/1331660993180/the-history-of-the-cheat-code

That's awesome! Some of my most favorite Happy Meal toys have been by Nintendo, whether it was the Super Mario Bros. figures way back in the day or Pokemon figures that were out only a few years ago.