Out of the 135 Pokémon available in Pokémon GO, Magikarp it really seems to be the most useless.
Even the Pokédex makes fun of him!
Magikarp is a pathetic example of a Pokémon capable only of wiggling and splashing around. The nature of this useless behavior is being studied by the scientific world.
Yeah, then why are they needed 400 candies to make it evolve?
Here is the answer:
The evolution of Magikarp is Gyarados, one of the most powerful (and rare) creatures available in the Pokémon universe.
Gyarados, however, must be earned: each captured Magikarp gives us 3 candies (one more, if transferred to Professor Willow), so you must have taken at least 101.
An already complicated undertaking for a normal Pokémon, let alone one of this type that should only appear near lakes, rivers or seas.
This video shows how convenient it is to evolve a Magikarp:
