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, Snivy was able to defeat him easily.
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 quickly defeated Ash's Pikachu again with his Cut. During the battle with Ash's Snivy, he was revealed to be male when he became infatuated with her after being hit by her Attract. As Servine was unable to attack, he was quickly defeated by her.
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 with Ash's Snivy, this time, however, he effectively stopped Snivy's Attract with a Leaf Tornado and came out victorious with one powerful Cut attack.
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.
In BW093, he battled Alder's Bouffalant and lost.
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 testiment 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 doesn't take most opponents seriously, unless said opponent is particularly powerful, as seen in BW093 when he was up against Alder's Bouffalant.