Accelgor first started off as a Shelmet in Enter Elesa, Electrifying Gym Leader! when it was originally Bianca's third Pokémon. It fought against Elesa's Zebstrika during Bianca's Gymbattle. It fought hard with its Acid and Energy Ball attacks, however, every attempt of an attack was dodged. A Flame Charge left it on the brink of defeat and sent it flying, and a Double Kick on the way down finished it off. Shelmet was still injured after the battle, and Bianca was worried, but Iris gave it some medicine and it felt better.
It later appeared in Evolution Exchange Excitement! where it was traded for Professor Juniper's Karrablast. The trade resulted in an evolution for both, and Professor Juniper was Accelgor's new owner.