How do you breed legendary Pokemon?
Most Legendary PokÃ©mon are incapable of breeding the only known Legendary PokÃ©mon that is capable of breeding is Manaphy and it is capable of breeding in all main series games since its introduction into the main series of games in PokÃ©mon Diamond and PokÃ©mon Pearl however Manaphy can only breed with Ditto and the resulting egg will cause the egg to hatch into Phione which will not evolve or transform into Manaphy.
Only Manaphy can breed. You need to leave it in the Daycare with Ditto to get a Phione egg.
Every single Legendary Pokemon in Pokemon Pearl can't breed no matter what. The only exception is Manaphy, which can be bred with a Ditto to form a Phione. But that's it; only Manaphy can be bred. All other Legendary Pokemon can't breed. Every single Baby Pokemon can't breed, either. Genderless, non-Legendary Pokemon can be bred with a Ditto.