It's Happini.
Im sorry, but there is no happiny egg in Pokemon platinum. You got diamond or pearl? trade from there
Breed a female Houndoom with a compatible Pokemon and hatch the Egg. I got the information from Pokemon.marriland.com
you get the manaphy egg in Pokemon rangers and send it into Pokemon diamond or pearl
You get a togepi egg in Pokemon Platinum, not Diamond.
no you already gave the manaphy egg away to your previous save
That is the only way to get a manaphy without cheating. once you get the egg in Pokemon Ranger then trade it to diamond/pearl/platinum and when it hatches then you have got a manaphy.
Have two Nintendo DS one have the Pokemon Ranger and one with the Pokemon Diamond. Then go to check egg. Then you have it.
Happiny
It is not possible to get a Lugia egg in Pokemon Diamond. It is generally impossible to get an egg of a Legendary Pokemon the only exceptions being Manaphy and Phione.
Manaphy is obtainable in Pokemon Diamond if you also have a copy of Pokemon Ranger. The game Pokemon Ranger is able to communicate with Pokemon versions; Diamond, Pearl, Platinum, HeartGold and SoulSilver to transfer a Manaphy Egg to them. This Egg can be hatched like any other Pokemon Egg.
happiny
you cant unfourtanately