As a wild Pokémon
Ambipom was first seen as an Aipom in Slaking Kong!, worshiping a giant Slaking with several other mountain-dwelling Pokémon. She also stole Ash's hat, much like Ash's Primeape did 428 episodes earlier, with a group of Aipom getting food to offer the Slaking. Later, Aipom joined the other Aipom, as well as several Mankey, Vigoroth and Slaking, to attack the giant Slaking, which turned out to be a mechanical robot made by Team Rocket. She then helped in returning the stolen berries to Taylor. Later, after Ash and his friends left Taylor's home, the group sees Ash's hat on a rock. After wondering who placed it there, they found out that it was Aipom, due to an apple and a flower she left with the hat. The group then continues their journey as Ash says Aipom is a cool Pokémon after all. Unknown to them, the happy Aipom was watching them from a nearby tree.
Aipom soon reappeared in the next episode, May, We Harley Drew'd Ya!, stealing the hats of the participants before making off with Ash's hat again.
In Thinning the Hoard, due to her causing too much trouble, Ash attempted to catch her. After Pikachu used Quick Attack to get Ash's hat back and Thunderbolt to weaken her more, she was still able to foil Ash's attempt to catch her.
In Channeling the Battle Zone, as well as the previous episode, after watching May in the Kanto Grand Festival, Aipom became thrilled with battling and challenged Ash and his Pikachu for a battle; as he won, Ash finally caught her in front of a huge crowd.
In Aipom and Circumstance!, Aipom became jealous of Pikachu's closeness to Ash. Aipom also seems to have a certain penchant for headgear; aside from taking Ash's and other participants' hats, Aipom wore a daisy chain on her head and put on a ceremonial crown that the locals had trouble getting off. The members of a crowd who wanted to crown, as well as Ash and his friends, attempted to remove the crown from her head so she would not become their king for a year. With the help of a Belue Berry's sourness, the crown was finally taken off. Ash then hugged Aipom and told her not to get into trouble all the time. As Ash laughed a bit when he told her this, Aipom blushed.
Aipom's gender was confirmed in the Japanese version of the said episode while Aipom was nearby gathering flowers. May said, 「エイパムやっぱり女の子ね？」 Aipom is a girl after all, isn't she?. In DP048, Dawn also explicitly calls Aipom a girl, and in the dub of Steamboat Willies!, both Aipom and Buneary are referred to as girls when Dawn saw them wearing dresses and excitedly exclaimed "Buneary and Aipom you girls look so cute!", confirming them to be female.
Aipom enjoys participating in Pokémon Contests, but is also eager to battle. Her interest was first perked in Thinning the Hoard! where she took an interest in May's battle with Harley. Aipom also watched her battle with Drew before enticing Ash into catching her. While Ash had Aipom, she usually sat on his left shoulder when outside of her Poké Ball, in contrast to Pikachu sitting on his right shoulder.
In order to bring back Torkoal to battle Brandon's Registeel in Overjoyed!, Ash sent Aipom to Professor Oak, where Aipom had trouble adjusting to the new environment and Ash's absence, even attacking the Professor. However, after Ash's second defeat, Aipom returned.
When Ash left for Sinnoh, he wanted to leave all of his Pokémon but Pikachu behind as he did when leaving for Hoenn. However, Aipom snuck aboard the boat he was traveling on to accompany him on his new journey. Aipom proved to be necessary as a backup; as soon as they arrived, Team Rocket kidnapped Pikachu, and Aipom helped find them. During her journey through Sinnoh, Aipom defeated Paul's Chimchar in battle and helped Ash catch his Starly.
In Mounting a Coordinator Assault!, Aipom was watching Dawn training with Piplup for the Jubilife City Pokémon Contest and became interested in participating. Seeing as how Aipom wanted to join the competition, Dawn and Brock convinced Ash to sign up. Ash and Aipom got through the Performance Stage, but in Arrival of a Rival!, they lost their first match in the Battle Stage to Zoey and her Glameow. After the battle, Zoey suggested that Ash should let Dawn raise Aipom.
In A Gruff Act to Follow!, Aipom put up a fight against Roark's Cranidos during Ash's Gym battle against Roark in the Oreburgh Gym, but lost.
In their rematch in O'er the Rampardos we Watched!, she went up against Roark's Geodude. Geodude managed to avoid a lot of damage from Aipom while countering with its attacks, but Aipom was able to connect a super effective Focus Punch and defeat Geodude. Aipom next went up against Rampardos. Aipom uses Swift, but it doesn't affect Rampardos at all. Rampardos uses Headbutt, but before Aipom could dodge it, it is hit and knocks out.
In Borrowing on Bad Faith!, Aipom entered an informal Pokémon Contest not sanctioned by the Pokémon Activities Committee under Jessie's command. It was able to advance to the final round, where it won against Dawn's Pachirisu, earning Jessie a year's supply of fruits.
In The Grass Menagerie!, Aipom was Ash's third and final Pokémon in his Eterna Gym Battle against Gardenia, she went up against Gardenia's Roserade after performing a contest like introduction. She used Double Team and began to get close to Roserade but Roserade used Grass Knot intending to trip Aipom up like Turtwig, although it destroyed the Double Team clones, Aipom herself was able to jump and avoid Grass Knot. Aipom then hit Roserade with Focus Punch, Roserade then used Magical Leaf, but Aipom dodged by climbing on the trees. Using its vines, Roserade was able to grab Aipom using its vines. Roserade then used Flash blinding Aipom, making her unable to hit with her Focus Punch. Roserade then hit Aipom with Magical Leaf, initially panicking, Ash was able to calm down Aipom and got her to listen with her ears instead as she was still blind. Roserade used Weather Ball, which was Fire-type due to the harsh sunlight, Aipom was able to listen for the Weather Ball and she then hit the Weather Ball with Focus Punch, punching it back to Roserade, dealing super-effective damage. Roserade then used Magical Leaf, but Aipom countered with Swift, opening her eyes as the effects of Flash had finished, the Swift then circled Roserade, then Aipom used Focus Punch on one of the Swift stars, knocking it into the Swift stars, causing them all to hit Roserade dealing major damage, Aipom then used the Focus Punch hitting Roserade, defeating the Bouquet Pokémon, winning Ash the Forest Badge.
In Throwing the Track Switch, Ash began the training for his next Gym battle in Veilstone City. However, Dawn's Buizel seemed to be more interested in Ash's battle training and thus couldn't set his mind on Dawn's training; Meanwhile, Ash's Aipom also had a problem in Ash's training because her style tended to be best suited for Pokémon Contests. Then, Zoey proposed that Ash and Dawn trade them. After some soul-searching, the Trainers agreed, and the trade took place.
In Journey to the Unown!, Aipom managed to learn Double Hit. Brock told Dawn that Aipom would evolve soon. Later in the episode, when Dawn and Aipom were being attacked by a group of Unown, Aipom jumped in and evolved into Ambipom.
In Team Shocker!, Dawn used Ambipom in the Performance Stage of the Solaceon Contest, but failed to advance to the Contest Battles. Zoey explained to Dawn that she failed due to an overuse of Swift, blocking Ambipom from view.
In Crossing the Battle Line!, Dawn used Ambipom in her Gym battle against Maylene. Ambipom was chosen for her extensive battling experience with Ash. She proved her strength in the battle by defeating Maylene's Meditite, making her the only Pokémon Dawn used in the match who managed to defeat one of Maylene's team. Despite this victory, Ambipom found herself unable to stand up to the strength of Maylene's Lucario and was quickly knocked out.
In Staging a Heroes Welcome, Dawn once again used Ambipom for the Performance Stage in the Wallace Cup. She managed to pass the round by dazzling the Contest Judges with Swift, Focus Punch, and Double Hit.
Ambipom battling Delcatty
In Battling the Generation Gap!, Dawn used Ambipom in the Battle Stage of the Celestic Contest. Ambipom was shown defeating a Delibird and a Nosepass to advance to the finals, where she went up against Lila's Delcatty. The battle started with Ambipom using Swift, which seemed to hit Delcatty. However, it was actually a decoy created through the use of Substitute while the real Delcatty sneaked behind Ambipom and wrapped himself up in her tails before using Shock Wave, landing a clean hit and costing Dawn some points. After that, Ambipom used Double Team and then Focus Punch, hitting Delcatty but unknowingly activating his Cute Charm Ability. This left Ambipom infatuated and allowed Delcatty to use Sing to put Ambipom to sleep. Delcatty proceeded to hit Ambipom with Iron Tail, sending Ambipom flying in the air and posing in an elegant manner while she was falling. The Prim Pokémon then used Shock Wave and the attack woke Ambipom up. Ambipom used Swift but Delcatty once again avoided the attack with Substitute. This time, however, Ambipom surprised Delcatty and attacked him with Double Hit, becoming infatuated in the process.
Despite the infatuation, Ambipom was able to use Double Team. Delcatty then used Sing but Ambipom used Double Hit to defend herself from Sing and attack Delcatty at the same time—something which inspired Ash to come up with the Counter Shield. When the infatuation wore off, Ambipom used Swift while spinning around to make the golden stars swirl. Delcatty tried to avoid the attack with Substitute but failed and then used Shock Wave. When the Electric-type move came into contact with the Swift stars, it formed a flat, rotating disk containing stars and dust at the center of the stage. Ambipom kept on using Swift on one side of the stage while Delcatty used Shock Wave on the other. A few seconds before time ran out, Swift broke through the disc and a massive amount of stars hit Delcatty. When the smoke cleared, Dawn was shown to have more points on the scoreboard, winning the battle and earning the Celestic Ribbon, her third Contest Ribbon overall.
In Old Rivals, New Tricks!, Ambipom was used in the Sandalstraw Town Pokémon Contest. In the Performance Stage, Dawn sent her out of her Poké Ball with a Song Seal and asked her to use Double Team followed by Focus Punch. Ambipom created multiple copies of herself and then punched all the musical notes with her long tails, taking advantage of the Seal's effect to begin her performance. Ambipom proceeded to use Swift as if she was serving a ping pong ball. She then spun around rapidly, causing the golden stars to move in a spiraling pattern before destroying them with Double Hit, which resulted in sparkles pouring down on both Ambipom and Dawn as they posed together to mark the end of the performance. The presentation was well received by the judges and allowed Dawn to move on to the second round.
In the Battle Stage, Ambipom squared off against Jessilina's Seviper in the semifinals and managed to win the battle. She proceeded to the finals, where she found herself up against Kenny's Prinplup. The battle started with Prinplup using Drill Peck, which Ambipom blocked with Swift before using 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. The bubbles were keeping Ambipom busy and Prinplup took the opportunity to try to attack 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. As a result, she lost the battle.
During the Sandalstraw Contest, she discovered a love and talent for ping pong. She used this talent to compete in the Pokémon Ping Pong Tournament with Dawn in To Thine Own Pokémon Be True. Due to her obvious natural ability, fellow competitor O offered her a place at his Ping Pong Training Center in Vermilion City. Dawn left the decision to Ambipom. After deciding to pursue ping pong over her love of Pokémon Contests, Ambipom bid farewell to Dawn and Ash and left the group in order to follow her new ambition.
She was seen in a flashback as an Aipom as one of Ash's Pokémon in League Unleashed!.