you cant. if you really want one then start again and get mudkip as your starter pokemon. evole it at LV 16 than you will have a marshtomp
Marshtomp evolves into Swampert starting at level 36.
at level 36
you could only get it as a starter Pokemon or trade it or breed it from the daycare get a marshtomp or a swampert and put it with a ditto and it will have an egg
get a fire type
Keep using Marshtomp's Mud Shot, it will lower their speed, and then you should use Water Gun.
Mudkip evolves into a Marshtomp at level 16.
Swampert can't be found in the wild. You have choose Mudkip as your starter Pokemon, and evolve it into Marshtomp (at level 16), then into Swampert (at level 36).
Mudkip, Marshtomp, Swampert, Zigzagoon, Linoone, Lotad, Lombre, etc.
Pokemon ruby's version IS Pokemon ruby.
Mudkip is a pure water type. It doesn't get its ground typing until evolving into Marshtomp and Swampert.
Wailmer Wailord Mudkip Marshtomp Swampert Lotad and it's evolved forms Magikarp and it's evolved form Tentacool Tentacruel
Mudkip evolves into Marshtomp starting at level 16, and then Marshtomp evolves into Swampert starting at level 36. Mudkip is #258 in the National Pokedex, and was introduced in the Generation III Pokemon titles (Ruby, Sapphire, and Emerald) where it was one of the starter pokemon. In Generation VI (X and Y), it is unobtainable by encounter. To obtain this pokemon, you must use the Poke Transporter to move it from another game, or trade for it with another pokemon player, since other people have them and breed them.