Oshawott's Lost Scalchop! (Japanese: 消えたホタチ！ミジュマル最大の危機！！ The Missing Shell! Oshawott's Biggest Crisis Ever!!) is the 31st episode of Pokémon: Black & White.
With Nimbasa City drawing closer Ash has a battle with a trainer named Stephan and his Blitzle. However, during the battle, Ash had to postpone the battle since Oshawott lost its scalchop. How will Oshawott defend itself without its prized possession? Will they ever find it again?
The heroes meet Stephan, a new trainer. Ash takes his challenge, sending Pikachu against Stephan's Blitzle. However, Oshawott comes out, pushing Pikachu away, as Oshawott wants to battle instead. Blitzle starts with Shockwave, though Oshawott uses his scalchop to deflect the attack, shocking Stephan. Blitzle uses Flame Charge and Oshawott uses Aqua Jet. However, the latter goes in a different direction and bashes into a rock. Oshawott uses Razor Shell, but gets intercepted by Blitzle's Double Kick. Oshawott's shell is blown away, so Oshawott runs off to find it. Ash goes after him, but Stephan thinks they are surrendering the match. Cilan points out that scalchop is part of Oshawott, so it does not mean they are surrendering. Iris thinks they will be back soon, so Stephan leaves and promises to come back tomorrow.
Oshawott tries to find his scalchop, but finds a bottle cap. Ash and Pikachu come to Oshawott, promising to find his scalchop. Ash finds something, so Oshawott puts it on his chest, but it is a Pokémon, who electrocutes him. Pikachu uses Iron Tail, bringing the Pokémon down, who is actually a Joltik. Joltik runs off, while Oshawott is sad. Ash promises they will find the scalchop, making Oshawott happy. Cilan and Iris come, reporting Ash's battle got postponed. Iris has an idea and runs off. Soon, she gives Oshawott a Iapapa Berry, while Ash goes to test it. Pikachu uses Thunderbolt on Oshawott, who tries to deflect it using the berry. The berry splits in two because of Thunderbolt, causing Oshawott to get electrocuted. Iris thought it would be a good idea to apply, though she and Cilan admit the berry has tastes good.
Cilan gives Oshawott his dish to hold. Oshawott uses the dish to protect himself from Thunderbolt, but gets electrocuted, for the dish is metallic. Cilan is terrified, for the dish is ruined. Ash asks to help Oshawott to make a new shield. Cilan sends Dwebble, who carves out a big shell from a rock, making a new shield for Oshawott. Pikachu uses Thunderbolt, though Oshawott lifts the stone shell, deflecting the attack. Ash is pleased the shield worked, but Oshawott falls down, as the shield is too heavy for him. Iris thinks Oshawott depends too much on the scalchop, but Ash disagrees, for it is not just a tool to Oshawott. Cilan thinks the best defense is a good offense, so Ash sees he needs to train Oshawott to use that shield.
Ash and Oshawott train hard. After a while, Pikachu uses Thunderbolt on Oshawott, who rolls away after being hit. However, Oshawott does not back down, pleasing Iris and Cilan for such determination, though Oshawott still gets blown away. Ash tries to encourage Oshawott to give a bit more, knowing how tough he is. During the night, Oshawott dreams his scalchop got lost and he got hit by Blitzle's Shock Wave. He remembers his master's words he can give even more, so is determined to become stronger. Ash and Pikachu search for Oshawott and find him trying to lift the stone shell. Ash offers more special training to Oshawott, who accepts. After some time, Pikachu uses Thunderbolt, but Oshawott deflects the attack using the stone shell without any mistakes.
Next day, the heroes anticipate Stephan, who has not shown up yet. They try find him, who is pedalling a generator to power up Blitzle. Stephan greets the heroes, showing he is powering up Blitzle. Stephan goes to battle Ash, who trusts in Oshawott. Blitzle starts with Shock Wave, though Oshawott uses the stone shell to deflect the attack. Blitzle powers up its Shock Wave, causing a crack in Oshawott's stone shell. Using Double Kick, Blitzle smashes the shell. Blitzle uses Shock Wave, though Oshawott takes a stone piece to protect himself, but fails and gets hit. Ash remembers Cilan's words, so orders tackle. Oshawott dodges Blitzle's Shock Wave and tackles it several times. Ash sees Aqua Jet is risky to use, while Oshawott cannot use the Razor Shell currently.
Blitzle uses Double Kick, which Oshawott dodges, including its Flame Charge. Blitzle cornered Oshawott and uses Flame Charge. Oshawott uses Aqua Jet, but, like other times, goes in a different direction. Oshawott's Aqua Jet clashes with Blitzle's Flame Charge and both are blown away after crashing into a rock. Blitzle is defeated, so Stephan calls it back and congratulates Ash on the victory. Stephan promises to train more and battle Ash once more, who is looking forward to it. Axew found the shell Oshawott lost and gives it to him. Oshawott puts it on his chest, pleasing him, but falls down, asleep. Cilan sees Oshawott is exhausted from all the training and battles. Ash thinks if one puts their mind to something, they can do anything.
- The Iapapa Berry looks a lot like a Figy Berry.
- Stephan uses the same trick Ash used in Showdown in Pewter City, except he's using a bike generator instead of a Hydro-Electric Plant's water wheel.
- The "Who's That Pokémon?" is Blitzle.
In this episode, Ash calls Razor Shell by its Japanese name (Shell Blade).