What about Pokemon that you expect to hit with a Grass Attack?
This list would be:
Dugtrio, Gyarados, Hippowdon, Mamoswine, Milotic, Starmie, Suicune, Swampert, Tyranitar and Vaporeon?
I guess I should be including a few neutral threats (besides Gyara which is already included) like:
Azelf, Cresselia, Deoxys-S, Dusknoir, Electivire, Gallade, Garchomp, Gliscor, Jolteon, Machamp, Snorlax, Spiritomb, Tentacruel, and Weavile.
I guess if I had to choose specifically from this list for neutral Pokemon I might leave something like say Celebi in against, it would be Cresselia, Dusknoir, Garchomp, Gliscor, Jolteon (to break subs), Machamp, Snorlax, and Tentacruel.