Empoleon was first seen as a Prinplup in Getting the Pre-Contest Titters!. It proved to be very strong when it was battling against Ash's Pikachu despite its disadvantage. In the next episode, it put up a good fight against Dawn's Piplup. At first Prinplup didn't want to be friends with its weaker, pre-evolved form, but after being saved by Piplup, they soon became friends.
In Old Rivals, New Tricks!, Prinplup was used in the Battle Stage of the SandalstrawContest. It managed to defeat its first two opponents to reach the finals, where it went up against Dawn's Ambipom. Prinplup started the battle by using Drill Peck, but Ambipom blocked the attack with Swift and then used Double Team. After that, Prinplup used Bubble Beam to destroy the illusory copies Ambipom had created. However, before the attack could hit the real Ambipom, Dawn had the idea to implement ping pong moves into the battle and asked Ambipom to use Focus Punch, sending the bubbles back to Prinplup.
Seeing that, Kenny asked Prinplup to repel the bubbles with Metal Claw. The bubbles went back and forth for a while until Prinplup used Bubble Beam again. This time, instead of repelling the bubbles, Ambipom used Double Hit to destroy them. With the bubbles keeping Ambipom busy, Prinplup approached her with Drill Peck, but Ambipom saw Prinplup coming and countered with Focus Punch. The two clashed in midair but Prinplup quickly recovered, jumping high and then using Drill Peck while nosediving and spinning. Ambipom proceeded to use Double Hit, but the move was unable to stop Prinplup. Ambipom was taken aback by this and Prinplup attacked her with another Drill Peck, knocking her out and winning the battle. This victory gave Kenny the Sandalstraw Ribbon, his fourth Contest Ribbon overall.
Natural of its species, Empoleon is always very proud and doesn't give others respect until they have, in its eyes, 'proved themselves worthy'. This was seen both when it met Dawn's Piplup for the first time and when it was pitted against Ash's Buizel. Like Buizel, Empoleon can be quite headstrong, developing their short-lived rivalry over a trivial issue, after Buizel's SonicBoom attack nearly hit its target.