Either evolve Magikarp or catch him at Lake Rage.
Gyarados do not evolve. Magikarp evolve into Gyarados at lvl. 20
lake of rage
You have to catch or defeat the red GYARADOS
you aren't supposed to defeat the red gyarados, you're supposed to catch it
you don't get one.but you can in Pokemon gold,silver,heart gold,and soul silver.
you find a red gyrados at the rage lake
magikarp will evolve at lvl 20 to a gyarados
he is at the lake of rage after you encounter the red gyarados
at the lake of rage outside of mahogany town
Talk to Mr.Pokemon after you get a red scale from the red gyarados
no, only evolving a magikarp it will be blue
bring it to mr Pokemon north of cherrygrove and you get a exp. share