Things You'll Need
Instructions
Access the Mystery Gift feature on "Pokemon HeartGold" or "Pokemon SoulSilver" for the Nintendo DS. You can find the Mystery Gift feature on the game's main menu after Professor Oak gives you the Pokedex in the game.
Select the "Receive Gift" option from the Mystery Gift main menu.
Select "Get Via Nintendo WFC" from the sub-menu.
Choose "Yes" when the DS prompts you to connect to the Nintendo Wi-Fi Connection.
Allow the system to search for a gift, which might take a few moments.
Choose "Yes" from the menu when the system offers you the option of receiving the rare Pokemon Mew. This option will only present itself during very rare Nintendo-designated Mew giveaways.
Allow the DS to download the Mew Pokemon. You'll hear a chime to confirm the download, and the system will display a message that reads "The gift has been received" and prompt you to pick up your gift in the game.
Visit any Poke Mart in the game to retrieve your gift. Your new Mew starts at Level 5 and comes with Pound, a basic normal-type attack. Mew comes inside a Cherish Ball and sports a Premier Ribbon to indicate the special giveaway event.
Save the game as soon as you retrieve your Mew; you don't want to risk losing this rare Pokemon.