Starter Pokémon, or Starters, are the Pokémon a trainer chooses at the beginning of their Pokémon journey.
In each generation of Pokémon games, a set of Starter Pokémon are available for new trainers to choose from in sets of three; the types that make up these sets are Fire, Grass, and Water. However, Pokémon Yellow is currently the sole exception to all the above, with Pikachu as the only starter available to the player.
All known Fire-type Starters are based on the Chinese Zodiac: Charmander represents the Dragon, Cyndaquil represents the Rat, Torchic represents the Rooster, Chimchar represents the Monkey, Tepig represents the Pig, Fennekin represents the Dog(Foxes are part of the dog family), and Litten represents the Cat.
Bulbasaur and Rowlet are the only Starters to be dual-type in their basic form.
All known Grass-type Starters possess reptile like attributes, except for Chespin and Rowlet and each have a type of plant on their bodies which grows bigger through evolution.
Most Fire-type Starters' final evolutions consist of two types. The only exception is Typhlosion.
In Johto, the Starters stay pure Fire, Grass and Water types throughout their evolutions. They never get a new typing.
All Water-type Starters are based on semi-aquatic creatures.
Starter Pokémon have unique special abilities: all Grass Starters possess the ability Overgrow, all Fire Starters possess the ability Blaze, and all Water Starters possess the ability Torrent.
Except for Pikachu and Eevee, all the Starters in any form can learn the ultimate attacks. Bulbasaur, Chikorita, Treecko, Turtwig, Snivy and Chespin can learn the ultimate Grass attack Frenzy Plant. Charmander, Cyndaquil, Torchic, Chimchar, Tepig and Fennekin can learn the ultimate Fire attack Blast Burn. And Squirtle, Totodile, Mudkip, Piplup, Oshawott, and Froakie can learn the ultimate Water attack Hydro Cannon.
However, both Eevee and Pikachu can learn what can be called the ultimate attacks in there respective type in any form. Pikachu can learn Volt Tackle, and Eevee in one of its evolved forms, can learn Hyper Beam.