In Facing Fear with Eyes Wide Open!, as soon as Ash and Oshawott tried to obtain some Remayo Weed from Palpitoad's territory, it shocked them with Thunder Shock and engaged in battle. It was fished out and caught by Cilan the same time that Ash captured his Palpitoad.
In Stopping the Rage of Legends! Part 2, it teamed up with Ash's Pikachu to stop the battle between the Kami Trio. Their combination of Thunderbolt and Thundershock stood well, but they were unable to win against them.
In Cilan Takes Flight!, it was used to battle Skyla's Swanna. Despite its Thundershock attack being 4x super effective, Swanna shrugged it off. Scald then burned it, but it recovered with Aqua Ring, and then brutally defeated him with Hurricane and Brave Bird.
Stunfisk was used in a double battle in New Places... Familiar Faces with Iris's Emolga to teach new trainer Nanette how to battle with her using her new Tepig and Ash using Pikachu. However the match was interrupted by Team Rocket.
In Pokémon the Movie: Kyurem vs. The Sword of Justice, Stunkfisk helped Cilan distract Kyurem's Cryoganal by using his Discharge to power an electric-operated train car. Despite holding them off and leading them away from Keldeo, he was easily stopped and frozen by Black Kyurem.
In the special episode of the XY series, Stunfisk was used by Cilan to save both Clemont and Bonnie from getting hit from a wild Clawitzer's Aqua Jet by using Mud Shot to make the wild Pokémon escape. Both Clemont and Bonnie are thankful to both Cilan and his Stunfisk.