The Kanto Starter Pokémon can be picked out of three Pokémon that the player will obtain in his journey which cannot be found in the Kanto Region itself. The three starter Pokémon are: Bulbasaur the grass-type Pokémon, Charmander the fire-type Pokémon and Squirtle the water-type Pokémon. These three have the abilities: Overgrow that will increase the Pokémon grass moves when the Pokémon has only 30% of its HP left, Torrent that will increase the Pokémon water moves when the Pokémon has only 30% of its HP left and Blaze that will increase the Pokémon fire type moves when the Pokémon has only 30% of its HP left. The abilities has not been known from Generation I and Generation II only since Generation III.
In Pokémon Green Version, Pokémon Red Version and Pokémon Blue Version, and Pokémon FireRed Version and Pokémon LeafGreen Version you will obtain a starter Pokémon from Professor Oak who have seen you walking in the grass at Route 1 and says that it was dangerous he will take you to his lab and gives you a pick on one of the three Pokémon. After you have picked up a Pokémon, your rival wants to battle you with a Pokémon that is strong against your starter.
In Pokémon HeartGold Version and SoulSilver Version you will obtain the starter Pokémon after having all the 16 badges and have defeated Red. If you talk to Professor Oak, he will give you a Kanto starter Pokémon of your choice. All of the starter Pokémon are at level 5.
In the Pokémon Yellow Version game, you will not receive one of the three starter Pokémon, but a Pikachu that has been captured by Professor Oak. Your rival will get a Eevee instead of a much stronger type than your starter Pokémon. You will obtain the Kanto starter Pokémon in the game, just as in the anime.
You will obtain Bulbasaur in Cerulean City from a girl only if the friendship between the player and his Pikachu is high. At the north of Route 24 a boy gives you a Charmander. In Vermilion City Officer Jenny will give you a Squirtle after you have defeated the Vermilion City Gym.
Pokemon X and Y
These Pokemon are available in Lumiose City from the Professor after defeating him in a battle. He will also give you a Mega Stone: