Well, there's already the Death Egg isn't there! I would give it a name involving stars or galaxies and something to do with more than one thing or the word 'multi,' combining both of them together. An example could be the Multi-Star or the Omni-Nebula. I'm also cool with the idea of it being another one of his egg machines, so you could call it the ____ Egg, like the Multi-Egg or Omni-Egg. If you want it to be something that isn't directly associated with Eggman, it could be just some sort of general term, like the Supernova, as an example. Something to do with stars or multiple galaxies I would say.