The Battle Club and Tepig's Choice! (Japanese: バトルクラブ！謎のポケモン現る！！Battle Club! A Mysterious Pokémon Appears!!) is the fourth episode of Pokémon the Series: Black & White, and the 661st episode of the Pokémon anime. It first aired in Japan on October 7, 2010 and in the United States on February 26, 2011.
As Ash and Iris continue toward Striaton City for Ash's first Unova Gym Battle, Iris tells Ash about the Pokémon Battle Club, a place where Trainers can battle each other to develop their skills. But after Ash accepts a challenge from a Trainer there, the Battle Club is suddenly closed down. It appears that someone-or something-has broken into the storage room where the food is kept! Based on the blurry image on the security tape, Ash thinks the culprit might be an Umbreon (a Pokémon that isn't native to Unova). But when Ash puts some Pokémon Food out to lure it, he and Iris are surprised to discover it's really a dirty, skinny Tepig, trying to scrounge for dinner.
Ash manages to calm the frightened Tepig and frees it from a rope that had been tied around its snout by an uncaring Trainer who abandoned it at the Club. With the rope gone, Tepig can eat again, and under Ash's care it quickly recovers its strength.
It turns out that Tepig isn't the only trespasser-Team Rocket has been attempting to steal supplies from the Club as well. But when Team Rocket kidnaps Pikachu, Tepig helps Ash with the rescue.
Iris then tries to catch Tepig for her own, but Tepig makes it very clear it wants Ash to be its new Trainer. After one quick maneuver with a Poké Ball, Tepig is our hero's newest friend! Ash decides then and there that he will use Tepig in his battle at the Striaton City Gym. Our heroes resume their journey, while a certain Team gets secret orders from the boss to travel to Striaton City for their next mission...
As Ash leaves the forest, he is amazed to see a large city in front of him. Thinking of it as Striaton City, he is pumped for the Pokémon Gym. However, Iris says that Striaton City is in fact the next town. Ash is feeling down but Iris tells him not to despair as there is a "Pokémon Battle Club". This piques Ash's curiosity, and he agrees to go.
Ash and Iris appear in front of a large green building, and they both enter. Iris explains how the battle club works on a computer inside. Four panels appear on the screen and Iris chooses the top left one with a picture of two Trainers. She goes on and says this is the Trainer's profile as pictures of Pokémon with their Trainers appear. As Iris goes on, Ash and Pikachu get more excited by the minute.
Ash and Iris enter a room with a Pokémon battle already started between two Trainers. One Trainer has a Dewott and the other Servine. Ash looks them up on his Pokédex. The Trainer with Servine tells it to use Leaf Blade, but Dewott blasts it back with a Water Gun attack. Servine falls near Ash and Iris, and a rather large announcer declares Servine's defeat. Servine's Trainer runs up and asks it if it is alright. The Trainer then runs out carrying the injured Pokémon. The announcer introduces himself as the battle manager Don George and Ash and Iris introduce themselves. Don George notices his Pikachu as he is not native to Unova. The winning Trainer asks Ash if his Pikachu is strong, and when Ash says yes, he is then challenged to a battle, which Ash accepts.
As Ash gets ready to battle with Pikachu, Oshawott stumbles out of his Poké Ball, wanting to battle. Despite Ash and Pikachu's reasoning, he pushes Pikachu to the ground and gets ready to battle. The other Trainer sends out Dewott, and upon seeing his evolution, Oshawott has his doubts and urges Pikachu to battle for him. Ash returns Oshawott to his Poké Ball, and Pikachu and Ash get their game face on for a brawl.
Ash tells Pikachu to start off with Thunderbolt, which Dewott evades. Iris comments on the Pokémon's speed. Ash then tells Pikachu to use Iron Tail, this time landing a clear shot. Dewott falls back near its Trainer, it then tries to get up. Seeing this as a chance, Ash tells Pikachu to use Volt Tackle, however Dewott evades at the last moment. The Trainer smiles and instructs Dewott to use Razor Shell, landing a clear hit.
Meanwhile, Team Rocket breaks into a nearby building, inside of which a silhouette of Pokémon can be seen. The Pokémon dashes out, causing Team Rocket to make a noise, setting off the alarm. Meanwhile, Ash's battle is put to a halt by the alarm. The announcer goes out and checks with his subordinates. Ash, Pikachu, and Iris dash out, curious on what happened. Over at the building, they inspect it but find nothing. They decide to check the security cameras. They are all then gathered in a room where a monitor shows the building's rooms in a 3D view. The video shows Team Rocket leaving the building in a hurry, followed by a dark black Pokémon. Ash uses his Pokédex to manually bring up the entry on the Pokémon Umbreon. Ash and Iris decide to help the manager find it. Ash sets out some Pokémon food as a trap, and leaves Oshawott and Pikachu to guard it. Instead, Oshawott eats all the food, and knocks Pikachu backwards into some boxes when the Mouse Pokémon tries to stop him. Many falling boxes hit Pikachu on the head, followed by a metal container, knocking him out. Ash sees a Tepig try to eat the food, but he could not, as he has a rope tied around his mouth. Ash attempts to help him, but Iris appears and scares him away. Ash manages to corner him and take the rope off of him. Meanwhile, Don George and his assistants are continuing their search for Umbreon. Team Rocket over hears them searching for Umbreon, so Jessie paints Meowth to look like an Umbreon, which Meowth is clearly not pleased with. He then lures Don George and his workers away from the building to give Jessie and James their chance to search the warehouses. When they catch up with him, they start crying tears of joy, but then he feels guilty and reveals himself as a Meowth painted as an Umbreon. After some initial disappointment, however, Don George and his assistants realize that a Meowth —even if he doesn't speak human— is also very rare in Unova, and decide to catch Meowth instead. However, Meowth left before he could realize this.
After feeding and cleaning Tepig, Ash and Iris take him back to Don George, who explains that Tepig belonged to an arrogant Trainer, who, after Tepig's defeat to a Deerling, abandoned him. In a sad attempt to follow his Trainer, Tepig got tied to a pole. Tepig broke free but still had a remnant of rope tied over his mouth. Just then, Team Rocket attacks and tries to steal Pikachu. Ash attempts to use Oshawott to save Pikachu, but is unable to. Then, Tepig decides to fight beside Ash. Ash orders an Ember attack, freeing Pikachu. However, Team Rocket manages to escape. Iris then decides to catch Tepig. However, Tepig decides to go with Ash instead.
Meanwhile, Giovanni is shown speaking with Team Rocket via a computer screen, telling them to head to Striaton City, for a certain area nearby needs investigation.
This is the first time since the first season that Ash has caught three Pokémon in three consecutive episodes. Coincidentally, the aforementioned three consecutive catches were also the regional starter Pokémon.