If you missed the recent Manaphy event, you've still got another chance to catch this Legendary Pokemon! Throughout the month of October, the Nintendo World Store in New York City's Rockefeller Center is sponsoring fun Pokemon activities and giveaways-including the distribution of Manaphy!

First of all:

• You must have a Nintendo DS, and an English version of either Pokemon Diamond or Pokemon Pearl.
• You will also need to make sure you have obtained the Pokedex.
• Make sure you don't have more than 2 Wonder Cards. If you do, you'll need to delete 1 to make room.
• You can only get 1 Manaphy on each Pokemon Diamond or Pokemon Pearl Game Card.

This spectacular Manaphy also includes:
Held item: Red Scarf
Poke Ball: Cherish Ball
Moves: Heart Swap, Water Pulse, Whirlpool, Acid Armor
Note: This specific Manaphy cannot be deposited on the Global Trade Station.

Sources: http://www.pokemon-games.com/ & PDF