The Quaker Oats Man is a demonic entity who was created via Satanic ritual in 1877, when Quaker Oats was founded. His enemy is the Pringle Dingle, AKA the Pringle's guy.
Whenever someone in Hyrule farts, Quaker Oats Man gains the ability to possess anyone who heard the fart within the next two minutes or so. This hazard has become well known throughout Hyrule, leading to the illegalization of farting in the country. Despite the ban, QOM once managed to possess King Harkinian after Link farted. Luckily, Link managed to defeat him by doing a kamehameha out of his butt.
"My barley's top of the shelf, I'm a man of my word."
"Time to rise and shine..."