first go to dewford by talking to Mr.Briney he will be chasing a wingull.when you mannage to talk to Mr.Briney he will take you to dewford.Talk to a man standing close to the boat he will give you a old rod then go up to some water select the old rod you will see a ! that means you have got a bite if that happens press A then you will enter a battle if it is a Pokemon you want catch it with a kind of pokeball.
That's basically how to catch it. Here's where you find it:
Firstly, you'll have a better chance of catching it if you use a super rod. Second, be very, very, very patient. It could take a while. Feebas can only be caught in 6 specific spots on the water in Route 119. go onto any body of water in Route 119. Fish on a spot. If you don't get a Feebas within 3 tries, that probably means that it isn't there. Repeat the process until either succession or you just become too impatient.
You should actually use the old rod to eliminate running into Carvanha.
On the Route southwest from Fortree City.
the rarest Pokemon in Ruby Sapphire and Emerald is Feebas
Only in ruby, sapphire and emerald at route 119
Since Feebas is a Water Pokemon,you can only find it in lakes,rivers etc.
THE MOST ANNOYING POKEMON IN THE GAME In the route beetween foretree and mauvile, there is 5 or 3 i cant remember, squares that contain feebas out of 400+!!!!!!!!!!!!
the only way to evolve it is to have the feebas at a high BEAUTY status for Pokemon contests. and the best way to do this is to have a feebas with a MODEST nature.
you can find a feebas in route 118 and 119 but its hard to find
You must evolve Feebas.
trade it from ruby or sapphire
Use a Gameshark
On the Route southwest from Fortree City.
the rarest Pokemon in Ruby Sapphire and Emerald is Feebas
super rod
Saphire Version
Feebas is found on the patch of water in the route to the LEFT of Fortree, in 6 Random squares, which change when the Dewford trendy phrase is changed. You will need to fish for Feebas.
Fish with super rod in route 119, BUT it is ultra rare.
Super rod is the best rod to use.