Simply because that's the best nature for gyarados. Raises it's att and lowers it's special attack. Because gyarados has very good attack stats and low special attack stats anyways it's best to raise what he's good at. Best way to train a gyarados is to give it max attack/speed and a lil bit hp EVs. In other words adamant nature is the best as it boosts attack yet doesn't lower speed/hp gain ;)
Adamant nature
same lvl as a normal magikarp 20 and the shiny magikarp evolves into a red gyrados
A Magikarp can evolve into a red Gyarados. The Magikarp needs to be a shiny Magikarp in order for it to evolve into a red Gyarados. This is due to the red Gyarados simply being a shiny Gyarados.
no lower its hp then use an great ball
First of all I'd like to say your spelling and grammar are bad, It should be: Where can I get a Magikarp In Pokemon Leaf Green; the answer: use the old rod In practically any body of water.
adamant nature is best
Adamant nature
adamant
A Magikarp should evolve at about lvl 40 on Pokemon diamond
Adamant, but it also lowers Special Attack. So if you're using a pure physical attacking Pokemon, Adamant is probably your best bet.
in my opinion its adamant cus i got my groudon attack in the 400's
Adamant
Dialga should hold the Adamant Orb.
Since its attack and special attack both are 438 when maxed out with a beneficial nature I'd say either Adamant or Modest. But if you want speed over attack you should get maybe Jolly, personally I like the Modest nature and I know many people also go with that.
it means your pokeman is adamant natured, thusly making the pokeman superior to all others.
All adamant armour like Adamant full helm, Adamant platebody, Adamant plateleg
the guy in the pool is CRAZY!! he's scared of a couple of magikarp! sorry guy's but that's right, the only thing you can catch is magikarp. lot's of magikarp! yep, the only good thing about it is that the magikarp range from level 1-100!! the pond should be called super-magikarp ' R ' US!! HA HA HA!!