Instructions
Evolve from Magikarp
Travel to Dewford Town.
Speak with the fisherman near Dewford Gym. Receive the "Old Rod."
Fish in any body of water until you hook a Magikarp.
Lower the Magikarp's health and capture using a "Pokeball."
Battle with your Magikarp until it reaches level 20 and evolves into Gyarados.
Catch Fully Evolved Gyarados
Travel to Mossdeep City.
Speak with the fisherman behind Mossdeep Space Center. Receive the "Super Rod."
Travel to Sootopolis City. Fish in the lake until you hook a Gyarados.
Lower the Gyarados' health and capture using a "Great Ball" or "Ultra Ball."