Where to find Koffing in FireRed & LeafGreen

Surf: Celadon City (1%)
Walk: Pokemon Mansion (30%)

• Celadon City — Surf
• Pokémon Mansion (3F, 2F, 1F, B1F) — Walk

Koffing in every game · Pokémon FireRed & LeafGreen interactive map (Kanto)