in the trophy garden after you get nat dex
at the Pokemon mansion after obtaining nat dex talk to mr backlot
regigigas isn't one of the 150 pokemon. he only in the national dex and his number is 486.
use the water stone on eevee. eevee found at the Pokemon mansion after obtaining nat dex talk to mr backlot
In the Sinnoh Dex, it's Turtwig. In the Nat Dex, it's Bulbasaur.
Capture all the Pokemon On the National Dex.
pichu in Sinnoh Dex exeggutor in National Dex
Regional dex-unown. National dex-tangela.
No.
Sinnoh Dex: Drifloon Nat Dex: Alakazam
im not sure that you can catch it in the wild, unless you have unlocked the survival area and got the nat dex, or you can migrate from older games.
all Pokemon can be traded (even eggs) to Leaf Green with out the nat. dex. with the nat dex. you can trade to emerald, ruby and Sapphire. but not to the older games like crystal and red