From Bulbapedia, the community-driven Pokémon encyclopedia.
Johnny (Japanese: ジオンビ Giambi) is a character of the day and a Pokémon Trainer who took part in the Double Battle rounds of the Ever Grande Conference. He appeared in Shocks and Bonds.
When Ash got to see Johnny's battle against Tyson, both Trainers had already lost a Pokémon. Tyson's Sceptile was up against Johnny's Aggron.
Sceptile used Detect and its speed to dodge Aggron's Metal Claw. Eventually, Aggron tired out and Sceptile was able to finish it off with a SolarBeam, even though it had used Harden. Tyson's victory allowed him to move on to the next round while Johnny was eliminated from the tournament.
This is a listing of Johnny's known Pokémon in the anime: