In the great marsh. I think you have to see it in the Binoculars first.
in great marsh you can find shroomish there is a 10 pesent chance of finding one good luck :)
shroomish can be found in pastoria great marsh but it changes by day so keep putting money into the binoculars until you see one.
You catch Sroomish in the great marsh, but he is very rare you can only catch after you complete the sinnoh dex
You can catch Shroomish in Pokemon Omega Ruby in rotting leaves deep in the forest.
Throw a pokeball at it
go 2 the forest n start headbutting those trees (:
You can only catch Vulpix in SoulSilver, not in HeartGold. You can catch it on route 36 and route 37.
you can get celibi on heartgold only from a wi-fi event
sorry, you can't catch them, you have to migrate them from the GBA game Sapphire/Rubymigrate
you get it in the bug catching contest
You will need to find one in the Safari Zone, or by headbutting trees in the Viridian Forest
you can catch shroomish at the pastoria great marsh between the levels of 27 - 31
Shroomish is a rare Pokemon in Ruby and Saphire but you can find it in the Petalburg woods.
Probably where you catch kyogre. (i don't know i used a repel.)
Safari zone, or head butt trees (after the league) to get a shroomish.
Headbutt a tree in the Viridian Forest, you might also get a shroomish.
You can't catch Rotom in heartgold.
you cant catch him in heartgold you can only get him in soulsilver
You can't catch him in HeartGold. Only in SoulSilver. In HeartGold, you catch Kyogre in Embedded Tower. If you transfer either Kyogre or Groudon to the other game, you can catch Rayquayza
In the woods where you go to rustboro, but u first have to catch a shroomish and evolve it
The Great Marsh. Check every day.
You can catch Ekans in Pokémon HeartGold in the Safari Zone in the Marshlands area.