A Breed Stampede! (Japanese: ポケモンと仲良くなる方法！？A Way to Befriend Pokémon!?) is the 106th episode of the Diamond & Pearl series, and the 572nd episode of the Pokémon anime. It first aired in Japan on December 11, 2008 and aired in the United States on May 16, 2009.
After hearing that her rivals Kenny and Nando have scored new Contest victories, Dawn is eager to train her newly-evolved Piloswine for their next competition. But Piloswine refuses to follow her commands and only shows an interest in eating Poffins! When the Poffin supply runs out, Piloswine charges and tries to put Ash's Grotle and Gliscor on ice. Luckily, Gliscor's new move, Fire Fang, counters Piloswine's icy blasts, and Brock's Happiny stops Piloswine in its tracks. Maybe a friendly Pokémon battle is what Piloswine needs, but it's not even interested in battling Grotle. It hits Grotle with Ancient Power, then abandons the fight when it smells food—Team Rocket's food!
Team Rocket is sitting down to a picnic when Piloswine runs up, freezes them in ice, and eats their cake. While Dawn wonders what to do with Piloswine, Team Rocket hatches a plan to take revenge for their lost lunch. They create a Pokémon Friendship School where Trainers can bond with their Pokémon; sure enough, Dawn sees their poster and decides this may help her befriend Piloswine. In fact, Ash and Brock decide to take Grotle and Croagunk to give the school a try, too! The first activity is an obstacle course, and everyone does great... except for Piloswine. Next, our heroes call out all their Pokémon for a brisk round of calisthenics, which also fails to interest Piloswine.
Finally, all the Pokémon are instructed to stand in a circle: all the better for Team Rocket to scoop them up in a cage! With their cover blown, Team Rocket hops in their balloon and tries to take off with the cage, but Piloswine forces a crash landing. Team Rocket's Pokémon attack, but that only triggers Piloswine's Evolution into Mamoswine! Mamoswine easily bursts free of the cage and blasts Team Rocket into the sky, but then it turns on Dawn and her friends. All Dawn can do is recall it to its Poké Ball and hope she can somehow find a way to befriend her out-of-control Pokémon. As for Ash, Byron the Canalave Gym Leader is back in town, which means the next Gym Challenge is coming right up!
Ash is training on the battlefield for his sixth Badge, but as Dawn calls out Piloswine, it refuses to obey her commands, though she dismisses this in the beginning due to Piloswine having only recently evolved. She commands her Piloswine to use Take Down, though instead it uses Dig to hide underground. Piplup volunteers to retrieve Piloswine, however this turns out to be the wrong move and as a result it charges Piplup for touching its fur. Nevertheless, this manages to get Piloswine above ground. Brock suggests that it might just be hungry. Therefore, Dawn gives it Poffins which certainly gets it moving when she throws it some. But after she stops giving Piloswine Poffins, it makes its dislike for her known as it charges directly at her, whilst knocking Piplup out of the way. Dawn and Ash begin running, as Piloswine charges and even starts attacking them with Ice Shard. Gliscor volunteers to help stop Piloswine, but Ash instead commands Grotle to help. Grotle stands its ground while being half-frozen with Ice Shard. Ash then commands Gliscor to use Screech. Unfortunately the attack doesn't stop Piloswine and Gliscor manages to get partially frozen, and Gliscor starts to tear up as usual when suddenly Gliscor's mouth starts to fill with fire which quickly melts the ice. The group realizes that Gliscor has just learned Fire Fang, and Gliscor uses its new move to free Grotle while Piloswine is now charging at Dawn and Ash again. Piplup is once again catapulted by the rampaging Piloswine and is saved by Gliscor. Then Brock calls out Happiny to stop Piloswine dead in its tracks with her incredible strength, which she manages to do. Ash suggests that maybe a battle is what Piloswine needs to bring it into line.
As Piloswine and Grotle battle, Piloswine constantly refuses to listen to Dawn's commands and attacks on its own, revealing that it is able to use Ancient Power. Suddenly an aroma sweeps by Piloswine, causing it to rampage out of the battle to the scent. It is revealed that the scent is from Team Rocket's sponge cake. As they are about to eat, they are hit with Piloswine's Ice Shard and blasted away. Just then the gang finally catch up with Piloswine as it munches on the cake and Dawn gets upset, as she realizes that she has completely lost control of one of her Pokémon.
Back at the Pokémon Center, Dawn sadly ponders over why she's having problems with Piloswine when she didn't have any with Swinub. Brock tells Dawn that when a Pokémon evolves, sometimes its personality will change along with its form. Dawn begins to wonder how it will be able to compete in the Chocovine Contest, but is comforted by Ash and Brock, reassuring her to be calm and that while it might take some time they would eventually become buddies. Spying behind a window, Team Rocket realize that it was Dawn's Piloswine, and create another scheme to stage. Inside, Jessie and James, dressed as "punks" become excited over a poster for Pokémon Friendship School, making sure to catch the group's attention. Dawn then realizes that the school can help her and Piloswine become closer.
They approach the school, to be confronted by Jessie in disguise. Jessie clamors about the exceptional friendship school. She leads the group into a tent filled with many obstacles. They each are told to choose one Pokémon to befriend. Ash chooses Grotle, Brock chooses Croagunk, and Dawn chooses Piloswine. But as Ash and Brock are properly maneuvering through the obstacle, Dawn's Piloswine simply avoids them, and sometimes will not move unless given a Poffin by Dawn.
After they reach the outside of the tent, they are brought down a cliff to the ground on a lower level to begin their "Friends Forever Course." They are met by James barely in disguise, who tells Ash and his friends to release all their Pokémon. James then tells them to do "Comprehensive Calisthenics" to establish Pokémon synchronicity. He then raises flags and maneuvers them into various postures. He then asks the Trainers and their Pokémon to move into the two circles, Trainers in the white circle, and Pokémon in the red circle, directly to the right. Piloswine has to be pushed by Piplup as it still refuses to move. James then continues and forms a ball form. As everyone crouches down to do the same, Meowth and Jessie (watching nearby atop the cliff) activates a hole beneath the Trainer's circle (but unlike the usual holes, this one was very short and easy to climb out of). Then a part of the cliff opens with a cage appearing and trapping the Pokémon. Team Rocket then recite their usual motto. Their balloon then rises, lifting the cage with the help of twin motors. Ash and his friends then command their Pokémon to attack the cage bars, without success. But the electric charge of Pachirisu's Discharge jolts Piloswine, who begins to panic and shakes the cage about, lowering the balloon and eventually crashing it. Jessie and James then call out Yanmega and Carnivine (who again begins chewing on James's head) to attack the Pokémon within the cage. But after a direct hit from Yanmega's Silver Wind, Piloswine begins to evolve! Piloswine evolves into a much larger Pokémon which easily breaks the cage. Brock tells Dawn her Piloswine has evolved into a Mamoswine and Dawn looks it up in her Pokédex. Jessie and James begin directing their attacks at Mamoswine, who uses Ice Shard to freeze them, and blasts them away again with Take Down. Even though Team Rocket are gone, Mamoswine is still angry and begins charging at Dawn and the group. Piplup, now with a score to settle, attempts to stop Mamoswine, however its attacks only enrage the Twin Tusk Pokémon further. Dawn doesn't have a clue about what to do, and Brock tells Dawn to return Mamoswine to its Poké Ball, which she manages to do in time. Knowing she can't enter Mamoswine in the Chocovine Town Contest now, Dawn ponders if she will ever be able to control Mamoswine, but is reassured by Ash and Brock that things will get better, she just has to take it slowly.
Back at the Pokémon Center, Nurse Joy gives the gang some good news as she tells Ash that Byron has finally returned to the Canalave Gym. Ash is now very excited, as he gets ready to battle for his sixth GymBadge.
Ash's Gliscor is half the average size of its species in this episode.
In the Japanese version, it shows Piloswine running between the two bars, with the camera moving. In the dub, it only shows it rushing through the first part, with the camera staying stationary, then Dawn saying, "Well, that's one way to do it..."