Brock awards Ash the Boulder Badge in the Pokémon TV series.
Brock is the Gym Leader of Pewter City and specializes in Rock-type Pokémon. Ash first challenges him after traveling west from Pallet Town. Although Brock’s Onix initially overwhelms Pikachu, Ash’s actions help produce an unusual victory: water from the Gym’s sprinkler system weakens Onix, and the Gym’s lights are extinguished before Pikachu can deliver the decisive attack.
Brock still gives Ash the Boulder Badge because he recognizes Ash’s determination and compassion. The badge is Ash’s first official Kanto Gym Badge. Brock then leaves Pewter City to travel with Ash, Misty, and Pikachu, becoming one of the series’ longest-running companions. Misty, Lt. Surge, and Erika are also Kanto Gym Leaders, but none awards the Boulder Badge.