How do you get hoppip in diamond?

Answer 1

In order to catch a Hoppip, you have to have the PokeRadar. (You can obtain the PokeRadar by seeing every Pokemon in Sinnoh. Then go talk to Professor Rowan; AKA the National Dex.) Go to Route 205 and use your PokeRadar on patches of grass and if you see a shiny sparkle on one of them, that means it is most likely a rare Pokemon. But if it just shakes, you can walk over it, but it's probably just a common Pokemon you see often. Anyway, walk over it, and if it isn't a Hoppip, just try again. But you have to walk another 50 steps to recharge the PokeRadar. By the way, this is Diamond, not Pearl. For Pearl you have to go to Fuego Ironworks and also use the PokeRadar.

Diamond Hoppip Levels: 9, 10, 11.

Pearl Hoppip Levels: 29.