I believe after you beat the viridian city gym leader he disappears.
in viridian city
It's just left out of Viridian City.
If you are excluding Pallet Town, then it'd be Pewter City after Viridian City.
It is in Viridian City right behind the pokemart and pokemon center
he is in viridian city and also he the leader of team rocket
You go to the elite four, west of viridian city.
You get it by beating Giovanni at the Viridian City gym, which you can't do until you have the other 7 badges.
Pewter city go north of viridian city and through the forest and u r there
In kanto, south of pewter city, north of viridian city.
In the Kanto region above Viridian City
You can get Pikachu in the Viridian forest south of Viridian City.
go through viridian forest