It was an event thing a long time ago. I dont remember when though. I had it in diamond but my game destroyed itself.
Chat with our AI personalities
No. Shaymin is a legendary, and therefore cannot breed.
You can't get shaymin in heart gold you have to trade it from Pokemon pearl,diamond or platinum.
Shaymin was only introduced in the 4th generation games (diamond, pearl, and platinum) and cannot be found or traded to Pokemon emerald.
You can't change Shaymin into Sky Form in Pokemon Diamond (that includes pearl). You can only change Shaymin into Sky Form in Pokemon Platinum (that includes Heart Gold and Soul Silver). You can get the Gracidea to change Shaymin into Sky Form.
you must trade shaymin from flower paridise in Pokemon diamond or pearl to platinum. then, go to the blonde girl in the middle of floraroma town and talk to her with shaymin in the front of you party. then equip it to shaymin and you have shaymin sky forme!