Ash's Pikachu

Ash's Pikachu is a Pikachu belonging to Ash Ketchum and one of the main characters of the entire Pokémon anime. In Pokémon Yellow Version: Special Pikachu Edition, which is based on the anime series, the player character has a Pikachu as their Starter Pokémon, and the Pikachu is based on Ash's Pikachu.

Pikachu is voiced by Ikue Otani throughout the anime series, except in the English dub of "Pokémon, I Choose You", in which Rachael Lillis provided the voice in cases when another character's voice overlapped Pikachu's.

Its first appearance in the anime is "Pokémon, I Choose You!". In the episode, Ash Ketchum, an inhabitant of Pallet Town, arrived late at Professor Oak's lab (having slept in from a late night of Pokémon trainer fantasizing). The traditional three starting Pokémon had already been taken by other new trainers, and Ash was given a Pikachu instead. At first, Pikachu largely ignored Ash's requests, shocking him frequently and refusing to be confined to the conventional method of Pokémon transportation, a Poké Ball. However, in the first episode "Pokémon, I Choose You!", Ash put himself in danger to defend Pikachu from a flock of wild Spearow, then rushed the electric mouse to a Pokémon Center (notably stealing Misty's bike to do so). Through these demonstrations of respect and unconditional commitment to Pokémon, Pikachu warmed up to Ash, and their friendship was formed.

The bond between Ash and Pikachu is a prominent motif in the series and inviolable in terms of the series ethos. Pikachu is the only Pokémon in Ash's party that has been with him in every episode, movie, and TV special. It is implied that Ash's Pikachu is male, but it is rarely addressed with a gendered pronoun. Also, many times Ash and Pikachu have been separated by cave-ins and explosions. Most of these times, Meowth is also separated from Team Rocket, and they usually end up working together to find their trainers.

It is explicitly shown that there is something 'unique' about Ash's Pikachu, setting it apart from others of its kind; Team Rocket's Meowth quips early on in the first series that Ash's Pikachu's powers greatly exceed that of even its evolution (which was shown in the battle with Lt. Surge's Raichu). For this reason, Team Rocket's attempts to capture Pikachu become a significant theme throughout much of the first series. It is shown in some episodes that they intend to present it to their boss, Giovanni, in order to win favour.

Early in the series, Pikachu underwent a training/conditioning regimen to increase the strength of the electric sacs in its cheeks in order to beat the first gym leader, Brock. In another first season episode (in Vermilion City), Pikachu, who is often rather independently minded, believed that it was strong enough without evolving and refused to evolve into a Raichu. In fact, in Ash's third gym battle in Vermilion City, Pikachu was successful in defeating a Raichu, and to this day, Ash's Pikachu has participated in more gym battles than any of his other Pokémon.

Throughout the series, there's a running gag involving Pikachu zapping the bike of the female protagonist. It first destroyed Misty's bike, which she used as an excuse to travel with Ash, then when Ash went to Hoenn, Pikachu destroyed May's bike. Most recently Pikachu destroyed Hikari's bike while defending itself from her Pochama. While the first actually had worked as part of the plot in order to add Misty to the main group, the laters were more of a reference to the original and served exclusively for comedy purposes, having no real influence in the story, other than forcing the female protagonist to walk instead of ride her bike.

As seen in the episode, "Showdown in Dark City", Pikachu's favorite "food" is ketchup (Pikachu is often seen licking the bottle when Ash and others are eating Omurice). In this case Ash's Pikachu kept the bottle and became slightly obsessed with it. This caused problems because a Scyther and an Electabuzz that were enraged at the color red were nearby. Scyther accidentally cut the bottle, spilling the ketchup, causing Pikachu to cry.

In one episode, it is stated that Pikachu feels that Ash makes rash choices sometimes. This statement is made by Anabel, after talking to Pikachu.