go under water out side of sootopolis then go in the front gr*** then you get it it took
me 1 hour

Relicanth is very rare so it's hard to get (near Lilycove City, I think). Good luck!

Its better if u use sweet scent

you go underwaterin front of sootopolis

Ok I know this is hard for some of you, but on my Emerald, I am SO lucky with rares!
My Rares:
Ana (Vigoroth)
lv. 20
Jasmin (Jigglypuff) (I find it on route 115. It's pretty rare. Big chance of getting
Swablu or Taillow instead.)
Lv. 25
Forry (Castform)
lv. 25
Tropius
lv. 26
Gina (Kecleon)
lv. 30
4 Skittys
Levels: all on lv. 20
Reli (Kirlia)
lv. 20
Kadabra
lv. 20
2 Plusles
Levels: both on lv. 20
Shroomishes
lev els: 20 & 22
Absol
lv. 28
Wynaut
lv. 20
Sparkly (Sableye)
lv. 26
Snora (Snorunt)
lv. 40
Relicanth
lv.33

you go infront of sootopolis and he is there.use an ultra ball

how do you get legandary dogs on pokemon firered?

you can get only 1 legendary dogs depending on a starter.
Bulbasaur = Entei
Squirtle = Raikou
Charmander = Suicune

And you can get them only after you beat ELITE FOUR. Sorry, that's all I know