Kenny had Piplup, who eventually evolved into a Prinplup before his Contest in Floaroma Town.
As Kenny met Dawn in Floaroma Town, he presented Prinplup. Dawn's Piplup wanted to greet it, but Prinplup pushed it aside, since it didn't like anyone standing in its way. Before the Contest, Kenny wanted someone to spar with, just to prepare himself, and challenged Ash and his Pikachu. Pikachu started with a Thunderbolt, which was countered by Prinplup's Metal Claw. Prinplup retaliated with Drill Peck, to which Pikachu spinned around to evade, then used an Iron Tail. After bouncing away with Bubblebeam to avoid collision, Prinplup clashed with Pikachu with Metal Claw and Iron Tail attacks. At this point, Team Rocket interfered with the battle, having Seviper use Haze to reduce everyone's vision. Ash's Staravia gusted the smoke away, revealing Team Rocket having captured Prinplup. Threatening to hurt Prinplup if they take another step, Team Rocket had their Pokémon attack the heroes. Piplup then used Whirlpool - a new move it learned - to absrorb attacks and engulf Team Rocket in it. Prinplup helped Piplup defeat Team Rocket with Bubble Beam, and after the incident was resolved, Prinplup was healed at the Pokémon Center.
In the final round of the Floaroma City's Contest, Kenny used Prinplup against Dawn's Piplup. The two sides clashed by using Bubble Beam, which spread glitter around. Piplup went to attack with Peck, but Prinplup used Metal Claw to stop the attack and toss Piplup away. Prinplup went to use Drill Peck, but Piplup defended itself with Bide and released the damage back to Prinplup. As Prinplup went to use Metal Claw, Piplup used Whirlpool to defend itself and stop Prinplup, binding it in the water. To get another chance, Prinplup used Mist, followed with Drill Peck, but was stopped again by Whirlpool. Instead, Prinplup got atop of the Whirlpool and clashed with Piplup, using Metal Claw against its Peck. At this point, time ran out for the round, and Dawn won the round, due to Kenny having less points than her.
In order to catch a Buizel, Zoey advised Dawn to battle it like it was a Contest, which reminded her of Piplup's Whirlpool it used against Prinplup. Kenny and Prinplup won a second ribbon. Dawn, who watched them from a television, swore she would catch up with them. Kenny and Prinplup reached Solaceon Town, where they met up with Dawn and others, to participate in the Contest. Kenny used Prinplup during the Solaceon Town's Contest, fighting Jessilina's Dustox. Prinplup went to use Drill Peck, but was stopped by Dustox's Psybeam. It levitated Prinplup with Whirlwind and pierced its Bubble Beam with Poison Sting. As time ran out for the round, Jessie, who had more points than Kenny, won the round.
While the heroes resided in Canalave City, they saw on TV that Kenny won his third ribbon with his Prinplup. While the heroes went to Snowpoint City, a flashfoward of Kenny and Prinplup confronting Dawn and Ambipom in a Contest was shown: Kenny and Prinplup visited the heroes at Sandalstraw Town, as he, too, wanted to participate in the Contest. As Piplup disappeared, Kenny and Prinplup helped the heroes in finding it, but Prinplup and Barry's Empoleon got attacked by Team Rocket, whose machine grabbed the two Pokémon. The two attempted to use Bubble Beam and Hydro Cannon, but the machine spinned them around to prevent them from attacking. As Pikachu used Thunderbolt to defeat them, Team Rocket used another machine to absorb electricity and electrocute Empoleon and Prinplup instead. Piplup later used Whirlpool to destroy the machine, setting the captured Pokémon free.
During the final round of the Sandalstraw Town's Contest, Kenny sent Prinplup to battle Dawn's Ambipom. Ambipom fired Swift to deflect Prinplup's Drill Peck. As Ambipom used Double Team, its illusions were banished by Prinplup's Bubble Beam, to which Ambipom reflected some of the bubbles with Focus Punch. Prinplup used Metal Claw to redirect the attack, causing both sides to bash the bubble as a ping-pong ball. Prinplup fired another Bubble Beam, which was countered by Double Hit. It then collided with Ambipom's Focus Punch, using Drill Peck. As Ambipom went to use Double Hit to counter Prinplup's Metal Claw, it failed and got defeated by its Drill Peck attack, earning Kenny the victory in the Contest.
Kenny had Empoleon team up with Floatzel: it used Hydro Cannon along with Floatzel's Hydro Cannon. Floatzel emitted a Razor Wind to scatter bubbles, and Empoleon's Metal Claw caused them to glitter. However, when they attempted to do a Flash Cannon-Whirlpool combination, the force of the attacks proved to much for Floatzel to handle and it accidentally knocked Floatzel out, causing Kenny to lose to the appeal rounds.
In Sunyshore City, Kenny was training his Empoleon, who used Hydro Cannon. Ash joined him, sending his Buizel for training. Buizel fired a Sonic Boom on a tree, which deflected onto Empoleon, but the latter repelled the attack. The next day, the two Trainers had a battle using those two Pokémon. Empoleon fired Flash Cannon but missed, so it used Drill Peck. Buizel intercepted the move, so Empoleon fired a Hydro Cannon. Buizel attempted to stop it with Water Gun but failed, and got hit. Empoleon went to use Metal Claw, so Buizel dodged and retaliated with Ice Punch. Empoleon dodged, and used Metal Claw, hitting Buizel. The latter attempted to use Ice Punch once more, but was defeated by Empoleon's Drill Peck.
- ^ Empoleon knew this move as a Prinplup, but executed it in 'DP174: Last Call—First Round!'
- ^ a b DP026: Getting the Pre-Contest Titters!
- ^ DP027: Settling A Not-So-Old Score!
- ^ DP034: Buizel Your Way Out of This!
- ^ DP055: Throwing the Track Switch
- ^ DP060: Journey to the Unown!
- ^ DP061: Team Shocker!
- ^ DP106: A Breed Stampede!
- ^ DP120: Mysterious Creatures: Pokémon!
- ^ DP122: Stopped in the Name of Love!
- ^ DP123: Old Rivals, New Tricks!
- ^ DP174: Last Call—First Round!
- ^ DP180: Four Roads Diverged in a Pokémon Port!