Starter Pokémon, or Starters, are the Pokémon a trainer chooses at the beginning of their Pokémon journey and the main protagonists of the Pokémon series of games. 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. Each starter Pokémon has three evolutionary forms. Pokémon Yellow , Pokémon Let's Go Pikachu and Pokémon Let's Go Eevee are currently the only exceptions to the above, with Pikachu as the only starter available to the player in Pokémon Yellow and Pokémon Let's Go Pikachu, and Eevee as the only starter available to the player in Pokémon Let's Go Eevee.
In the core series games (with two exceptions), the player can choose a fire, water, or grass-type starter Pokémon at level 5. At least one of the player's rivals will also always choose or have a starter Pokémon, typically the one that has a type advantage over the player's while the other choose the one that has a type disadvantage over the player's. it is also said that the starter Pokémon are extremely rare in the wild, giving the player a reason why the Pokémon not chosen can't be found in the wild.
In Pokémon Diamond and Pearl, when two Starly attack the player and rival at Lake Verity, to which they travel upon hearing reports of a red Gyarados, they will choose between Turtwig, Chimchar, or Piplup from Professor Rowan's briefcase, which he left at the lake.
In Pokémon X and Y, the player, Shauna, and Serena/Calem receive their starter Pokémon: Chespin, Fennekin, and Froakie in Aquacorde Town from Tierno, who was asked by Professor Sycamore to deliver them.
In Pokémon Sun and Moon, the player receives their starter Pokémon: Rowlet, Litten, and Popplio in Iki Town from Hala and Professor Kukui. In Pokémon Ultra Sun and Ultra Moon, the player receives one from the Professor on Route 1. The player's friend Hau will choose the Pokémon with a type disadvantage to the player's choice. Teacher Emily in the Trainer's School will use the starter that has a type advantage over the player's choice.
In Pokémon Sword and Shield the player and Hop receive their starter Pokémon: Grookey, Scorbunny, and Sobble in Postwick from Leon, the Pokémon Champion of Galar. The player's friend Hop will choose the Pokémon with a type disadvantage to the player's choice. Leon takes the remaining Pokémon into his care, eventually using its final form in the Championship Match against the player.
Go initially wanted his starter Pokémon to be a Mew like the one he met when he was six, but he changed his mind after befriending a wild Scorbunny in Galar, choosing it as his partner instead.
Caught in the wild instead
Certain characters in the anime have caught a regional Starter Pokémon in the wild instead of having them as their first Pokémon.
Ash caught a Bulbasaur, a Charmander, and a Squirtle in quick succession in the Kanto region. Of the three, only Charmander evolved, becoming a Charmeleon, and later a Charizard, both of which were very disobedient to Ash until an incident in the Orange Archipelago, after which it served Ash as it had when it was a Charmander. Bulbasaur was also going to evolve, but decided to stay as itself than becoming an Ivysaur in Bulbasaur's Mysterious Garden.
Ash caught a Treecko in Hoenn, while Brock captured a Mudkip. Treecko evolved twice, becoming Sceptile before Ash left it at Professor Oak's lab, while Brock's Mudkip evolved into Marshtomp. Along with May's Torchic, the traveling trio had the three starter Pokémon of Hoenn.
May caught a Bulbasaur midway through her journey in Hoenn, and was given a Squirtle by Professor Oak when she journeyed to Kanto. Bulbasaur evolved all the way into Venusaur and Squirtle evolved into Wartortle during May's travels through Johto.
In Sinnoh, Ash repeated himself by catching Turtwig, which has since evolved into a Torterra. His rival, Paul, owned a Chimchar that was confirmed to be caught in the wild. It was released, recaught by Ash, and is now an Infernape.
Dawn hatched a Cyndaquil during her journey in Sinnoh. It later evolved into Quilava.
Ash reused his pattern from the original series of catching all starter Pokémon in Unova: Oshawott, Tepig, and Snivy. However, this time around, he caught them in reverse of the Pokédex order rather than following it as he did in the original series, and Oshawott was in fact a starter Pokémon that Professor Juniper allowed Ash to have after it ran away to be with him. Of the three, only Tepig has evolved, becoming a Pignite.
Gary Oak had an Eevee at least since Ash was traveling in the Orange Archipelago. As it was revealed to be under his ownership before his Blastoise, it caused many to hearken back to Pokémon Yellow, where the player starts with Pikachu, like Ash, and the rival starts with Eevee. Either way, it was disproven that this was the case when Gary finally revealed his Blastoise to Ash. His Eevee eventually evolved into Umbreon.
Ash caught a Froakie in Kalos, which used to belong to several other Trainers before being abandoned or abandoning the Trainer. It has since evolved into a Greninja.
While Ash was in Alola, he caught a Rowlet who was living in a flock of Pikipek, a Trumbeak, and a Toucannon. Ash also encountered a Litten a few times before finally earning its trust and capturing it. Litten has since fully evolved into a Incineroar.
Go caught a Scorbunny in Galar, which started out as a common thief who stole people’s foods to feed its fellow thieves, the three packs of Nickit. Scorbunny officially joined Go in SS005, where it became his first Pokémon.
All of the core series starter Pokémon have the gender ratio of 7 males to 1 female, with the exception of Pikachu.
This gender ratio was chosen to make the starters harder to obtain.
Bulbasaur and Rowlet are currently the only Starters to be dual-types in their basic forms, as aside from both of them being Grass-types, Bulbasaur's also a Poison-type while Rowlet's also a Flying-type.
However, Rowlet loses its Flying type and becomes a Ghost type.
In Unova, the Starters also gain signature attacks unique to them: Snivy gained Leaf Tornado, Oshawott gained Razor Shell and Tepig gained Heat Crash. Leaf Tornado and Razor Shell were given to other Pokémon in later generations.
Each one of their final evolutions have an immunity: Decidueye, a Ghost type, is immune to the Normal and Fighting types, Incineroar, a Dark type, is immune to the Psychic, and Primarina, a Fairy type, is immune to the Dragon type.
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.
The Elemental Monkeys are similar to the starters and are given in a similar manner.
Except for Pikachu and Eevee, all the Starters' final evolutions can learn the ultimate attacks by move tutor upon reaching maximum happiness. Grass-type starters can learn the ultimate Grass attack Frenzy Plant; Fire-type starters can learn the ultimate Fire attack Blast Burn; Water-type starters can learn the ultimate Water attack Hydro Cannon.
Most of the rival trainers will choose the starter that has the type advantage over the starter selected by the player. Bianca, Shauna, Hau and Hop all instead choose the starter that has the type disadvantage.
Sceptile gains Dragon-type as a secondary type on Mega Evolving, making it the only Mega Evolved starter to gain a new type (Charizard was already dual when the Mega X version replaces Flying with Dragon).
The player can later catch the first evolved forms of both the Kanto and Kalos starters in some Grass, Fire, and WaterFriend Safaris. This marks the first time any Pokemon related to starters have been available to catch in the wild.