* Trade over the GTS * Find them yourself * Migrate them from a GBA Game Pak
buy the Pokemon platinum book
you find them in the cave
you see all the Pokemon in platinum and trade from your other games like emerald, blue, fire red etc and that is how you find all Pokemon in platinum.
You can find a bunch of Pokemon but i realy don't want to list them.
You can find a Hippopotas in Pokemon platinum at "Ruin Maniacs Cave". If you need to find something else about Pokemon go to Serebii.net. They have all the information about Pokemon! I hope I helped!!
you can find them in gartinas cave
you need to download your Pokemon platinum game into the R4 and add cheats in there . Go to Supercheat to find the cheats
You have to defeat all the trainers and find all the Pokemon
if you find a website about Pokemon platinum AR codes email me at landonmeador@gmail.com
You have to find all of the Pokemon in Sinnoh.
all you have to do is evolve lickitongue
find them in grass