LIst of pokemon that can appear in the dream world and thier rarity?

Question

I wanna contray snivy and a torrent panpour

Answer 1

http://www.serebii.net/blackwhite/dreamworldareas.shtml

to get to the other areas other than pleasant forest you need to get more points by playing mini games

unfortunately torrent panpour and contrary snivy have not yet been released but there will probably be an event soon if were lucky