There are hundreds of Pokemon that you can catch in Pokemon Brilliant Diamond and Shining Pearl. However, you can get Pokemon in other ways. The Happiny pokemon can be obtained by hatching an egg. Here is how you can get a Happiny Pokemon in Pokemon Brilliant Diamond and Shining Pearl.
How to get Happiny
You can get Happiny in Hearthome City. Travel into Hearthome City and go to the south-eastern exit of the city, near 209. You will find an NPC here who is a mountain climber.
Talk to the Mountain Climber NPC and he will offer you an egg that he found at the Pokemon Nursery in the Solaceon Town.
Accept the egg and you need to take 10,000 steps for it to hatch. You can use your Poketch to calculate your current steps. The egg will hatch into Happiny after 10,000 steps.
What is a Happiny?
Happiny is a normal-type Pokemon that is first introduced in Generation IV. This pokemon is egg-shaped and you can evolve it into a Chansey if you level up Happiny while holding an Oval Stone. There are no male Happiny in the game.
Happiny can also evolve into the Blissey once you reach a high enough friendship level.