they wander from region to region. when the pokedex shows them in a route/town, don't fly to it. they'll move by the time you get there. every time you change route/town they will to. if you change route/town without flying they will move to an adjacent route. check the pokedex everytime you change so you can corner it.
Once it's in the same route/town as you are you can begin looking for it like any normal pokemon.
in viridian forest
In Pokemon Yellow, the only obtainable Pikachu is the one you receive from Professor Oak. You have to cheat or trade to obtain another Pikachu.
You can't get pikachu in Pokemon colosseum you can see it but that's all, if you want pikachu you would have to trade one from firered, leafgreen, ruby, sapphire or emerald.
If your reffering to 'Pikachu' (#25 in the Kanto and national pokedex.) you can find it in a lot of places. Your best bet is going to 'Seribii.net' In Pokemon FireRed/LeafGreen you can find it in Viridian Forest.
The easiest place to find one is at the Power plant down the stream from the Pokemon Center at the entrance to the Rock Tunnel. But if you want to catch it early on in the game, Pikachu can be found in the Viridian Forest, although rarely.
While you can catch it in Viridian Forest, you can't get it as a starter. In Pokemon Yellow, an original Gameboy game, you can get Pikachu as your starter.
Pikachu can be caught at either the Viridian Forest, or the Power Plant.
In Pokemon Yellow, the only obtainable Pikachu is the one you receive from Professor Oak. You have to cheat or trade to obtain another Pikachu.
You can't get pikachu in Pokemon colosseum you can see it but that's all, if you want pikachu you would have to trade one from firered, leafgreen, ruby, sapphire or emerald.
yes you can its really common to find one anywhere especially in the power plant .
Raichu never evolves. Unless you meant Pikachu, which evolves into Raichu. Or Pichu, who isn't in Leafgreen but evolves into Pikachu, then Raichu.
Caterpie, Weedle, Metapod, Kakuna, Pikachu.
If your reffering to 'Pikachu' (#25 in the Kanto and national pokedex.) you can find it in a lot of places. Your best bet is going to 'Seribii.net' In Pokemon FireRed/LeafGreen you can find it in Viridian Forest.
Rare. Virdian Forest and Power Plant.
In Pokemon FireRed and LeafGreen, Pikachu learns Thunder at level 41. It can be sooner when given the TM Thunder.
You have to catch him/her.Pikachu is found in Viridian Forest and at the Power Plant.
You cannot find pikachu in pokemon black.
You may have to train your Pokemon to at least level 20 or use a electric type like pikachu you can catch it in viridian city but its rare to find.