You get it from Professor Oak from Kanto. In Professor Rowan's lab after you beat the Champion and complete you Sinnoh Pokedex.
you're mumbling buddy! theres no such thing on platinum pearl and diamond its called its called the national pokedex and a sinnoh pokedex
POKEMON PLATINUM stupid!
I think it is ROTOM.
easy battle the ghost type gym
After you beat the elite four Oak will pop up if you caught 60 or more Pokemon he will give you the national dex
Persian is no.53 in the pokdex
ABXY
Sadly, no. The creators of the game forgot to add in the Pokedex, so trading is impossible without GameShark. :(
You do not need the national pokedex in platinum, simply talk to Bebe in Hearthome city
Complete pokedex (Select) 94000130 FFFB0000 B2101140 00000000 00001174 01011903 E0001178 00000018 01010101 01010101 01010101 01010101 01010101 01010101 D2000000 00000000
it is a dragon type Pokemon gym
use action replay