About the bad eggs

[kakashidragon]

I remember one time when i was playing my firered game that my hitmonlee changed into a bad egg for some reason.(not by gameshark i didnt own one at the time this happen,but i still dont have gameshark yet for the GBA)
If this topic is in the forums somewhere then please move this too it, I couldnt find this topic in the 3rd gen. area tho.

[Shiny Espeon]

Oh, bad eggs....I hear they appear when you've used a gameshark, or by some other means. I can't recall it off the top of my head, though.

Did you buy a used game? Maybe someone used a gameshark before you bought it, or it could just be a weird glitch.

[FreezeWarp]

Bad Eggs can be the result of countless cheats, as Shiny Espeon has said. I believe they can also be a result of some glitches, such as Pokemon cloning, though I haven't heard of that being possible in FireRed. Partial Data Corruption (you know, the "Saving Data... Don't turn off the power!") could also be the cause. A final possibility, which I have personally experienced, is that hacked ROMs loaded onto a flash cartridges and sold on eBay are known for countless of these glitches.