Jolteon first appeared in the Pokémon Tower where Jolteon fought against Team Rocket's Koffing. Jolteon used Quick Attack but Koffing used Smog, so Jolteon wasn't able to see and missed its attack. Cubone however came and cleared the smog with Bonemerang. Jolteon was able to see again and defeated Koffing with Thunderbolt.
Red also used his Jolteon in the Indigo League. Jolteon faced Lorelei's Dewgong and Jolteon seemed to have defeated Dewgong because Red advanced to the next Elite Four member. Jolteon faced Blue's Pidgeot and defeated Pidgeot with Thunder. Jolteon then faced Blue's Blastoise and Jolteon was defeated by Blastoise's Skull Bash.
|Quick Attack||File 2 - Cubone|
|Thunderbolt||File 2 - Cubone|
|Double Kick||File 3 - Giovanni!*|
|Thunder||File 4 - Charizard|
|+ indicates this Pokémon used this move recently.*|
- indicates this Pokémon normally can't use this move.