You Get It When You Visit Professor Rowan After You Get Your Starter Pokemon!
you compete the sinnoh dex.
Diamond and Pearl Sinnoh Dex: 46# Wormadam Platinum Sinnoh Dex: 46# Wormadam
you should find every Pokemon in sinnoh. i going to find all the pokemons in the national dex ;)
Pokemon #080 (Sinnoh Dex) is Barboach.
In Diamond & Pearl's version of the Sinnoh Dex, Pokémon #149 is Dialga.
By seeing all of the Pokemon there are in Sinnoh.
Complete the sinnoh dex
In the sinnoh dex,it is Feebas In the national dex,Omanyte
Spiritomb
it doesnt matter with time. you just have to have seen all the Pokemon in the sinnoh dex
Sinnoh Dex: Drifloon Nat Dex: Alakazam
In Sinnoh Dex it's unown and in national dex it's tangela.