Viridian Forest.
level 30!
trade from LeafGreen or FireRed.
You have to trade from FireRed or LeafGreen to get one.
lvl ten
Caterpie, Weedle, Metapod, Kakuna, Pikachu.
You don't catch Butterfree. You need to evolve a Metapod.
You can find it in Eterna Forest while LeafGreen/FireRed is inserted in your ds
caterpie, metapod, weedle, kakuna, pidgey, pikachu, and i think pidgeotto might be in leaf green, but it is in Pokemon yellow
Metapod evolves into Butterfree.
Metapod, but only if you catch it as a metapod.
Metapod evolves into Butterfree at Level 10.
Metapod evolves into a Butterfree at level 10.