Ronald McGiygas is Giygas' boss at work, and is also an alter ego of Ronald McDonald. Not a lot of people warmed up to the idea that this was really Ronald McDonald, unless, of course, you are a conspiracy theorist that really knows the secrets behind the junk you're eating at McDonald's!
Like Giygas, Ronald McGiygas was really overwhelmed with the idea of something bad happening to our world, although he didn't exactly plan to take it over. He instead planned to turn it into a GIANT HAMBURGER SO IT COULD FEED!!! Luckily he quickly dismissed this plan so he could go to night school and learn how to worship Satan. Good thing he didn't eat our world, because located in ITS body are believed to be OVER 9000 DIMENSIONS OF PURE TERROR!!!
Final Days of an UnMultiverse
After participating in the War of the Negaverse, Ronald McGiygas sacrificed himself by transporting Eggman Nega into the future using his own time-traveling powers. Unfortunately, when one travels without using a time machine (or Chaos Control), one is exposed to the untimely effects of the time stream. Thus, Ronald McGiygas melted away into the time stream and died, becoming a timeless hero for all Giygas clones. At least until Chuck Norriseegee revived him...
...and accidentally Weegified him.
Ronald McGiygas, for a time, outputted more energy than the entire UnOmniverse, causing spacetime to snarl in his wake. At the very center of the Negaverse, a low-end retcon event happened: powered by the Fakegas's time travel and Norriseegee's stare, McGiygas was retroactively rejuvenated to such an extent that he was able to consume NGC 4216 and avoid being stared at in the first place by sending the Fakegee across multiverses. In fact, the only way we know Norriseegee was even involved was because of the absurd level of power required to Weegify McGiygas. Shortly afterwards, McGiygas warped out of reality and into the void of the UnOmniverse, dangerously close to the UnMultiverse Beta Version, which he proceeded to consume. Eventually, a hole was opened to Dimension 666, which proceeded to envelop McGiygas and expand the dimension to millions of times its former size. He still sits there today, content with his meal.