Serperior was first introduced as a Snivy in Professor Juniper's lab, where he was chosen by Trip as his starter Pokémon in In The Shadow of Zekrom!. Shortly after obtaining him, Trip challenged Ash to a Pokémon battle and used Snivy against Ash's Pikachu. As Pikachu was unable to use Electric attacks due to an encounter with Zekrom, after enduring Pikachu's Quick Attack and Iron Tail, Snivy was able to defeat his worn out opponent with Leaf Tornado. Snivy and Trip then left Nuvema Town on a journey through Unova.
Prior to Triple Leaders, Team Threats!, Snivy was shown to have already evolved into a Servine, when Ash challenged Trip to another Pokémon battle in a Battle Club in A Rival Battle for Club Champ!. He first faced Pikachu again, meeting Pikachu's Iron Tail with Cut and landing a powerful hit with Leaf Tornado. He then managed to stop Pikachu's Volt Tackle and win the match with another Cut. Servine then battled Ash's Snivy, where he dominated the match by dodging her Vine Whip and Leaf Blade attacks before hitting Snivy with another Leaf Tornado. However, he was eventually hit by Snivy's Attract, becoming immobilized by infatuation. It was in this state that Servine was defeated by a frenzy of Snivy's attacks.
It was revealed by Cilan that Servine defeated Chili's Pansear in Trip's battle for the Trio Badge.
Servine appeared again in Ash and Trip's Third Battle! in Trip's 3-on-3 battle with Ash. He once again battled against Ash's Snivy, starting the match with Leaf Tornado, which proved even to Snivy's Leaf Storm. He then went in for a Cut attack, but Snivy dodged and used Attract. However, Servine was able to defend against the move, this time, with Leaf Tornado. He then stopped Snivy's Leaf Blade and defeated her with Cut.
In BW090, Servine was shown to have evolved into a Serperior and was used by Trip in the Pokémon World Tournament Junior Cup. In the first round, it went up against Burgundy's Darmanitan and managed to freeze it in place with a Leer. Then, it easily knocked it out with a powerful SolarBeam, giving Trip the win.
Then in the next episode, Serperior battled Marufuji's Heatmor in the second round and won with the same combination. Serperior soon battled Cilan's Crustle in the semifinals, and though Leer proved useless, he hit his opponent with another powerful SolarBeam. After avoiding Crustle's X-Scissor and Rock Slide attacks, Serperior finished the battle with a brutal Frenzy Plant. During the final match in BW092, Serperior battled Ash's Pignite, revealing his Dragon Tail attack while avoiding every one of his opponents attacks. He beat Pignite, as he beat Crustle, with a SolarBeam and a Frenzy Plant. As a prize for winning the tournament, Trip and Serperior were granted a battle with Unova champion Alder. Serperior's opponent was Bouffalant and he started the match by launching a SolarBeam attack. Serperior's opponent was revealed to have the ability Sap Sipper in the episode after, thus taking no damage from the attack. Regardless, Serperior hit his opponent with a Dragon Tail and a Leer attack while Bouffalant just stood there. Serperior's second Dragon Tail sent Bouffalant flying across the field but it quickly recovered and hit Serperior with Head Charge, knocking him out.
Serperior was full of determination, and was brimming with energy when he was a Snivy as seen in In The Shadow of Zekrom! during the battle with Ash when he was confident enough to defeat Ash's Pikachu. He has retained this trait after evolving. Also, Serperior has very little trouble dealing with opponents who have a type-advantage, a further testament to his strength.
True to his species norm, Serperior holds his head high pretentiously while fighting and tends to stay elegant at all times. He does not take most opponents seriously, unless said opponent is particularly powerful, as seen in BW093 when he was up against Alder's Bouffalant, bowing his head to Alder when the champion talked to him and stroked his chin.
