The first Gym Leader you will face on the road to collecting all eight
Kanto Gym Badges is
Brock. He is the
Pewter City Gym Leader, specializing in Rock Type Pokemon. Because Brock is faced so early in your journey, his
Pokemon Team won't be all that difficult to defeat regardless of the
Starter Pokemon you selected. However, if you did pick
Bulbasaur or
Squirtle as your
Starter Pokemon, you will have the clear advantage over Brock since he is especially weak against both Grass Types and Water Types.
If you happened to choose
Charmander as your
Starter Pokemon, you will probably need to add an additional Pokemon on your way to
Pewter City to better help you with
Brock's Geodude and Onix. The best Pokemon for this job is Mankey, which can be found on
Route 22 just west of
Viridian City. In addition to being weak against Grass Types and Water Types, Brock's Rock Type Pokemon are also weak against Fighting Types like Mankey.
Click Here To Learn How To Easily Defeat Gym Leader Misty!