12level cap
Brock fields 2 Pokémon between level 10 and level 12 in Pewter City Gym.
This is around Beat Brock — Pewter City Gym, badge 1 in the story — that page lists everything you can have caught by this point.
Types on this team: Ground ×2Rock ×2
| Pokémon | Ability & item | Moves | Base stats | |
|---|---|---|---|---|
 | Geodude Lv 10 RockGround | Tackle Defense Curl Rock Throw | HP40Attack80Defense100Sp. Atk30Sp. Def30Speed20Total300 | |
 | Onix Lv 12 RockGround | Constrict Screech Bide Bind | HP75Attack80Defense160Sp. Atk65Sp. Def65Speed85Total530 |
How to beat this team
Shared weaknesses. Fighting hits 2 of 2, Grass hits 2 of 2, Ground hits 2 of 2, Ice hits 2 of 2.
Level to be ready for. Lv 12 — Onix, the highest on the team.
Fighting Pokémon you can have caught by this point. From this guide’s own encounter tables, by Beat Brock — Pewter City Gym, badge 1: