Pokémon (1997)

S1E73 To Master the Onixpected!

Inspired by a televised match featuring Elite Four member Bruno, Ash and his friends head to the mountains to enhance their skills and match his strength. To their surprise, they run into Bruno, who cleverly convinces them to handle various chores for him. As they tackle these tasks, a colossal Onix wreaks havoc nearby, adding urgency to their training efforts.