How did Pokémon Ranger give Diamond and Pearl a Manaphy?

Manaphy could not be caught, bred or found anywhere in Diamond and Pearl. The only honest source in 2007 was a different game entirely. Finish Pokémon Ranger's story and a hidden service, Ranger Net, can be opened on the title screen with a button code, R, X and Left pressed together in the Western versions; in Japan, the missions it holds were originally tied to pre-ordering tickets for the ninth Pokémon film. Inside waits a mission called Recover the Precious Egg!, in which the Go-Rock Squad has stolen a Manaphy Egg from Professor Hastings.

Clear the mission and the Egg is yours, but it cannot hatch in Fiore. With a second DS running any Generation IV game, the Egg is sent across by local wireless through Mystery Gift, and it hatches in Sinnoh into Manaphy, the Seafaring Pokémon, which can then be bred with Ditto for Phione, the closest thing Generation IV has to a renewable Mythical.

The catch is written into the cartridge and every collector should know it: one Egg per copy of Ranger, ever. Ranger Net cannot be reset, and not even erasing your save file and finishing the game again restores the mission's prize. A used copy of Ranger may already have given its Manaphy away, which makes the cartridge a spent ticket or an unspent one, with no way to tell from the box.

The two Ranger sequels repeated the arrangement with Manaphy Egg missions of their own, delivered as Wi-Fi downloads, which means those eggs died with the servers in 2014. The first game's egg, locked behind a button code and one long mission, remains the durable one: still earnable today, exactly once.