A glitch involving Wonder Trade has been found.
This glitch starts off when a Pokemon traded using Wonder Trade becomes a “Mystery Egg”. The egg is a result of the data becoming corrupt during the trading process. You will receive a Pokemon but once the Pokemon is in your PC Box then it will become a “Mystery Egg”. The Mystery Egg will then proceed to multiply within the box and even turn the Pokemon in the box into Mystery Eggs.
The Mystery Egg is a result of the game’s procedure to handle corrupt data. Normally corrupt data results from hacking Pokemon or other similar situations which will result in a “Bad Egg”. The difference between the Mystery Egg and Bad Egg is that one of them doesn’t multiply like in the current situation. The Mystery Egg will multiple and lead to filling up your box with Mystery Eggs and eventually corrupting your game.
This glitch has been around since the day after the game has been release but has only been brought to the public’s attention due to news that Pokemon XY has been hacked. The possibility that there may be more hacked Pokemon being traded via Wonder Trade could raise the chances of receiving a Mystery Egg. Though, there has not been reported cases of this happening as of right now.
Please remember, it is still safe to Wonder Trade. Players just need to be a little bit more cautious.
There has been no word from Nintendo or Pokemon concerning the issue but hopefully like the Lumiose City Glitch, a patch will be released eventually. Click below to find out what to do if you find a Mystery Egg in your PC.
If you have a mystery egg, here are some of the things you should/shouldn’t do (taken from the thread taken above):
1. Do not touch the egg! That means no checking moves, stats, anything. It may have an item attached, do not attempt to retrieve the item!
2. The box the bad egg is in is immediately QUARANTINED.
3. Immediately remove all Pokemon from the quarantined box. They can and WILL be corrupted if they remain in close proximity to the bad egg.
4. Do not , I repeat, DO NOT attempt to withdraw the egg. Do NOT attempt to hatch the egg.
5. Your primary goal is to save all your Pokemon from infection. Treat a bad egg like you would a zombie pathogen that spreads via air.
6. Your secondary goal is to avoid the Pokemon “——-“. At all costs.
More information can be found here.