From Bulbapedia, the community-driven Pokémon encyclopedia.
Scalchops (Japanese: ホタチ hotachi) and seamitars (Japanese: アシガタナ ashigatana) are a type of shell weapon used by Oshawott, Dewott, and Samurott. Oshawott and Dewott use scalchops, while Samurott uses seamitars.
Oshawott has a scalchop on its chest, Dewott has one scalchop on each hip, and Samurott's seamitars are tucked inside the scabbards on its forelegs. These are detachable, and are often thrown. They are used in the execution of the move Razor Shell when performed by a Pokémon with a scalchop or seamitar.
Scalchops are made of the same material as fingernails, known as keratin, and are capable of regrowing if they happen to get destroyed. According to a book in the Nacrene Gym, Oshawott's scalchop grows from its bellybutton.
In the games
Oshawott attacking Charizard
with his scalchop in PokéPark 2
The scalchop can clearly be seen on the sprites of Oshawott and Dewott, and the seamitars can be seen on the sprites of Samurott. It is also seen in the animation for Razor Shell, visibly slicing into the opponent.
In Pokédex 3D, each of Oshawott, Dewott, and Samurott's animations shows them removing their scalchops and seamitars.
In PokéPark 2: Wonders Beyond, Oshawott uses his scalchop in battle. He is capable of throwing it like a boomerang, or slashing opponents with it like a sword. Dewott also uses its scalchops in battle, and to help Oshawott train. Samurott unleashes powerful blows with his seamitars that can cause geysers.
In the anime
Ash's Oshawott without his scalchop
Scalchops are shown to be vital to Oshawott, and its evolutionary family's survival, as it provides defensive and offensive benefits. According to Professor Oak's Live Caster, an Oshawott uses its scalchop to break open Berries, and only lets those it truly trusts touch it. Cilan also mentions that a scalchop is actually a part of an Oshawott's body by some extension in Oshawott's Lost Scalchop!.
Ash's Oshawott frequently relies on his scalchop to defend him against moves that would typically have an advantage over him, such as Bullet Seed or Shock Wave. It often will fall off of his stomach onto the floor and give the opponent a temporary advantage until he is able to retrieve it. In Oshawott's Lost Scalchop!, it actually went completely missing and Oshawott learned to battle using a stone scalchop replacement, and later with no scalchop at all after the replacement was destroyed. However, by the end of the episode, Oshawott's scalchop was recovered by Iris's Axew.
A Dewott was first seen using its scalchops in The Battle Club and Tepig's Choice! to execute Razor Shell while battling Ash's Pikachu. Later in A Connoisseur's Revenge! Burgundy's Dewott used its scalchops against Cilan's Dwebble.
In both Victini and the Black Hero: Zekrom and Victini and the White Hero: Reshiram, Leeku's Samurott used its seamitars against Ash's Tepig.
In Crowning the Scalchop King!, Scalchop Island was shown, an island celebrating Oshawott and Dewott. The island is shaped like a scalchop and its inhabitants sell merchandise based on it, such as T-shirts and souvenirs, but also food wares shaped like scalchops.
Unlike the manga, it is implied that if a scalchop is lost or destroyed then it can never be replaced.
In the manga
Oshawott hitting Tepig and Snivy with its scalchop
In the Pokémon Adventures manga
Bianca's Oshawott tends to use his scalchop to attack anyone who injures him, typically Tep and Snivy. This first occurs when the two knock Oshawott into a machine, and later when Black releases them from their Poké Balls. Oshawott's scalchop was a major asset during the Striaton Gym battle in Their First Gym Battle. It was used as a boomerang and managed to knock out Chili's Pansear, but was then immediately shattered by Cilan's Pansage. Cilan explains that scalchops are capable of regrowing after being damaged, much like a fingernail.
Oshawott using its scalchop in the anime
A Dewott using its scalchops in the anime
Samurott using its seamitar in the anime
Artwork featuring Samurott holding its seamitar
||From 帆立 hotate (scallop) and 太刀 tachi (a type of sword)
||From scallop and chop
||From coupe (cut) and coquillage (shell)
|Spanish (Latin American)
||From caparazón (carapace) and concha (shell)
||From 가리비 garibi (scallop) and 칼 kal (knife)
||From 扇貝 shànbèi (scallop) and 貝 bèi (shell)
||Means fan shell
||From 海驢 ashika (sea lion) and 刀 katana (a type of sword)
||Possibly from sea, seal, and scimitar