Where can you get Ho-oh in Pokemon Pearl?

Answer 1

It is a very long, difficult process.

1. In Pokemon Colosseum, snag and purify ALL shadow Pokemon

2. put your best Pokemon team in your party (if you need to trade from ruby, sapphire, emerald, etc. do so now)

3. Complete BATTLE MODE's mt. battle (using your story party) without a gameover.

4. Ho-oh will be transfered to the game's PC

5. Trade it to ruby, sapphire, emerald, firered, or leafgreen.

6. Migrate it to Pokemon Pearl

This is the only remaining way to get a legit Ho-oh. Or wait for Pokemon Heart Gold.