Corphish stood by Tierno when the incident of Vaniville Town happened. Just as they met up with Viola and accepted her proposal to come to her Gym, Shauna protested, since there could be danger ahead. Heeding her advice, Tierno sent Corphish, since they needed to be alert.
While sliding on his roller skates, Tierno descended down a railing, where he faced a Team Flare admin. The admin was furious and had Flygon attack Corphish. X arrived and showed on his Pokédex how Corphish would never release its prey with its claws, while Corphish pointed at the railing. While X had his Pokémon distract the admin, Tierno slided down the railing and launched Corphish. Corphish grabbed Flygon by its wing, causing it to fall down and drop the Team Flare admin. By this experience, Tierno even copied some of Corphish's moves while moving on his roller skates.
Just as they faced the Team Flare grunt, who wanted to take a Mega Stone meant for X's Manectric, Tierno sent Corphish to battle the grunt's Espurr. Since Corphish and the other Pokémon had trouble dealing with the Espurr, Cassius arrived and settled the problem with his Gourgeist.
In Laverre City, Tierno, along with his friends, was training with his Corphish, under Gurkinn's supervision. Along with his friends and the Gym Leaders, Tierno and Corphish went to Geosenge Town, to seal the Ultimate Weapon. There, Corphish tried to push the "bud", but Tierno called it back before he pulled Shauna and Trevor away, per Olympia's orders. Inside Team Flare's headquarters, Corphish used Guillotine, which snapped AZ's prison bars. Shauna complimented Corphish, for its training with Gurkinn made it learn a new move.
Corphish was walking with the group and looked up to Blue's Charizard and Rhyperior, who inspired Corphish to become as strong as they were. Corphish was used to find the Mega Stones, Pinsirite and Absolite.
Tierno and Corphish set off with the group to the Pokémon Village. As Tierno went to the Pokémon Village, he was taken by Mable. Swearing he won't lose, Tierno sent Corphish against her Houndoom. Her Houndoom melted Tierno's Roller Skates with Inferno, which halted Tierno. Tierno swore he wouldn't give up, as his Corphish, who pinched Houndoom, wouldn't let go. Thus, Corphish evolved into a Crawdaunt.
Crawdaunt lifted Houndoom and defeated it and Mable with Guillotine. After meeting up with Shauna, Tierno and Crawdaunt went with her to surround Aliana and her Pumpkaboo. The two gave up on interrogating Trevor, seeing they were surrounded.
In the end, Crawdaunt was with Tierno, who went with his friends to Vaniville Town.
|+ indicates this Pokémon used this move recently.*|
- indicates this Pokémon normally can't use this move.
- ^ X&Y001: An X-cuse to Come Out and Play
- ^ X&Y002: X-actly What They Wanted
- ^ X&Y005: Kangaskhan... Kangascan't
- ^ X&Y008
- ^ X&Y017
- ^ X&Y019: Overthrowing a Tyrunt
- ^ X&Y020: Morphing Manectric
- ^ X&Y026: Tying Trevenant
- ^ X&Y029: Quilladin Stands
- ^ X&Y030: Gyarados Changes
- ^ X&Y031: Pyroar Breathes
- ^ X&Y032: Flabébé Blooms
- ^ X&Y036: Hawlucha Attack
- ^ X&Y037: Pinsir Changes
- ^ X&Y039: Malamar Traps
- ^ X&Y041: Charizard Transforms
- ^ a b X&Y045: Xerneas Gives
- ^ X&Y046: Epilogue