What is the name of the Pokémon that evolves into Gyarados?

Magikarp is the Pokémon that evolves into Gyarados. In the main Pokémon games, Magikarp evolves into Gyarados when it reaches level 20, transforming from a famously weak fish into a powerful serpentine Pokémon.

Magikarp is usually associated with the move Splash, which does nothing in battle in most games. It can be caught early through fishing, and one memorable non-player character even sells a Magikarp to the player. Training it can seem pointless, but reaching level 20 rewards the player with Gyarados, making the pair one of the franchise’s best-known examples of dramatic evolution.

The transformation draws on the Chinese legend of carp leaping over the Dragon Gate and becoming dragons. Gyarados also changes type from Water to Water/Flying and is known for its destructive temper. A common mix-up is Feebas, another weak Water-type Pokémon that evolves into Milotic, not Gyarados.