Pikachu was Ash's Starter Pokémon, given to him by Professor Oak. Ash showed up late to pick his first Pokémon so he got stuck with Pikachu. Though he didn't like Ash at first, Ash demonstrated willingness to sacrifice himself for Pikachu, and they quickly became friends. Pikachu, who is rather independent in general, believes that he is strong enough without evolving and refuses to evolve into a Raichu even when he was easily beaten by Lt. Surge's Raichu. Later in Ash's adventure in the Sinnoh region, Pikachu was given another chance to evolve after being seriously injured by another Raichu but once again he refused.
Early in the series, Pikachu was given an operation to increase the strength of the electric sacs in his cheeks in order to beat the first Gym Leader, Brock. Despite of this, Pikachu can also get a cold and go out of control when he cannot release his electricity. Most notably, exposure to a magnetic field will cause Pikachu to get a cold. This has been done to him three times in the series, two times by Team Rocket and one time by Zekrom: the first time, Pikachu was cured when the extra electricity was used in attacks against a group of Grimer and Muk, and in the second time was inadvertently cured by one of Team Rocket's battery robots, which subsequently overloaded and exploded. The last time is when Professor Juniper heals him after Ash's battle with Trip in Unova.
Many of the Pokémon animated shorts with all-Pokémon dialogue have featured Pikachu as the main character, and as the main voice of reason. As such, Pikachu is often a leader, helping to break up conflicts among other Pokémon.
Pikachu is one of Ash's most powerful Pokémon being able to defeat pseudo-legendary Pokémon such as Metagross and Dragonite and even actual legendary Pokémon such as Regice. He was also capable of fighting Tobias' powerful Latios to a draw, despite the fact that Electric type moves are not very effective against Dragon types. Pikachu was used in many of Ash's Gym Battle Frontier and League battles, being able to defeat Juan's Milotic, Lt. Surge's Raichu (although this was during their rematch), Clair's Gyarados, Crasher Wake's Gyarados, Volkner's Electivire, Roxanne's Nosepass and her Geodude, Brock's Geodude and Onix, Roark's Onix, Brandon's Regice and countless other opponents.
However there are times when Pikachu gets beaten fairly easily. For example he was easily defeated by Lt. Surge's Raichu during their first battle, was no match for Sabrina's Kadabra, got knocked out by a single Night Shade from Morty's Gastly, which was Morty's weakest Pokémon, was overwhelmed by Fantina's Drifblim despite his type advantage, lost against Norman's Vigoroth in their first battle, landing only one blow in the process and was defeated in many other battles during his journey with Ash. Despite these defeats Pikachu was considered to be one of Ash's most powerful Pokémon, alongside Charizard, Sceptile, Infernape and Snorlax.
Pikachu's high level of electrical power has even allowed him to defeat Ground types more than once by using Electric attacks, which normally would do no damage at all. This is notably impossible in the games, where Ground-types take no damage from Electric-type moves under any circumstances, no matter how powerful they are. Whilst travelling through Hoenn, Pikachu learned how to use Iron Tail, which has become one of his signature moves, granting him a technique that will hurt a Ground-type normally, especially if they are also part Rock-type, as many Ground-types are.
In BW020: Dancing With the Ducklett Trio!, a group of Ducklett dropped an umbrella on Pikachu as he was about to use Thunderbolt, which affected his electric attacks as a result. Soon after, Pikachu learned Electro Ball and defeated the Ducklett with this move. He then battled the Sunglasses Sandile. During the battle, Sandile evolved into Krokorok and fired a Stone Edge at Pikachu, who used Electro Ball and sent the move back at Krokorok, blasting it off in the process.
In BW044: The Club Battle Finale: A Heroes Outcome!, he was used to battle Iris' Excadrill during the final round in the Don Battle Tournament at Nimbasa City. Because of a weakness to Ground-types, he was unable to defeat the Subterranean Pokémon and lost.
In BW052: Dazzling the Nimbasa Gym!, he was used in Ash's fourth Gym Battle against Elesa's Emolga (however, he had to use Thunderbolt on Ash beforehand to get his attention to use him, in frustration, as Ash did not even reconsider using Pikachu just once). For this matter, Ash lets Pikachu back in the battle and become friends once again as he leaves all of his plans behind him. Pikachu countered Emolga's Electro Ball with his own and defeated it with Quick Attack. Against her Tynamo, Pikachu suffered many direct hits of Tackle, due to Tynamo's amazing speed, until Ash commanded him to use Thunderbolt to alter the battlefield (this way Tynamo would be forced to Tackle Pikachu head on only). Ash's tactics work and Pikachu used a powerful Iron Tail to land a direct hit on Tynamo as it crashed onto the wall as a result to be knocked out, earning Ash the Bolt Badge.
In BW067: Battling the Bully!, the Sunglasses Krokorok returns to confront Pikachu to a battle (after he followed them all the way from Nimbasa Town, Nimbasa City, Driftveil City, and Chargestone Cave). However, this battle caused them to get blown away in separate directions after the interception of Pikachu's Electro Ball and Krokorok's Stone Edge. However he was found by a boy named Mick who was mistaking him as a pre-evolved form of Zekrom as he show him to his friends Glen and Shaun (who eventually knows this Pokémon from the Kanto region he went to). Now that Mick doesn't know how to battle with Pikachu, he goes away for a while to ask Pikachu some questions alone but was found by Ash and co. including Krokorok. Although Mick persuades Ash to let him borrow his Pikachu so he could battle with Glen and Shaun when Glen says the word "Let's Battle". Since Ash won't leave a kid like Mick in trouble like this, he agrees to as they do some training while Ash use Krokorok as an example for Mick to learn about type advantage and type disadvantage with Pikachu. However Pikachu's move of Iron Tail that Mick used cause Krokorok to lose his sunglasses but eventually found it and puts back on and gets angered to get him to pay Pikachu back but stopped by Ash. After training, Glen found Mick with Ash's friends as Mick put this Pokemon battle to a test with Pikachu but in one condition: this battle requires a double battle as Krokorok teams up with Pikachu just to help him out to battle Scolipede and Seismitoad and win this by brains and skills. Pikachu's teamwork with Krokorok was great as Glen learns his lesson that winning isn't for everything and make it up to Shaun and Mick once more. But then there's a score to settle when Krokorok wanted to has this battle with Pikachu as Ash agrees him to and made a type disadvantage to a win as a result to defeat Krokorok. In the end, the Sunglasses Krokorok felt bad when he lost to Pikachu. Which Ash made the decision to let Krokorok come with him and Pikachu making him his sidekick and a friend indeed. In BW070: An Amazing Aerial Battle!, Pikachu was used in a Gym Battle against Skyla's Unfezant and defeated it with Electro Ball. He stayed in the battle to fight Skyla's last Pokémon, Swanna. Pikachu's Thunderbolt and Electro Ball were blocked by Swanna's Aqua Ring, defending against the type advantage Pikachu held over it. However, using the hoops that Skyla had used in her pre-battle show, Pikachu was able to jump with Quick Attack to hit Swanna. Eventually, Swanna was able to hit Pikachu with a powerful combination Hurricane and a brutal Brave Bird, after which Ash deemed Pikachu unable to battle, although he didn't faint and he tried to continue.
In BW086: Rocking the Virbank Gym! (Part 2), Pikachu was the final Pokémon to go up against Garbodor. It was going to use DoubleSlap but Pikachu evades it and hits with Quick Attack and then Thunderbolt. When Pikachu tried to use Iron Tail, Garbodor swung its arms upwards, repelling Pikachu and untying the arms. After Pikachu dodges Gunk Shot twice, Garbodor grabbed him and used DoubleSlap hitting Pikachu repeatedly. After this, Garbodor fired another Gunk Shot, this time it hits and also poisoned Pikachu. To Ash's luck, Pikachu's Static ability got activated and paralyzed Garbodor after making physical contact with Pikachu. Despite still being able to withstand a Thunderbolt, the Trash Heap Pokémon was unable to take a hit from the following Electro Ball, and was knocked out, making Ash the winner and earning him his eighth and final Unova Badge, the Toxic Badge.
Pikachu is voiced by Ikue Ōtani in all versions of the anime, except in early episodes of the English-dubbed series, in which Rachael Lillis provided the voice in cases where another character's voice overlaps his. A running gag is how he burns all of main female character's bike with Thunderbolt, which, in turn results in that girl following Ash, except for Iris following Ash after she and Ash bumped into each other. Pikachu also has a fondness for ketchup, which is seen multiple times in the anime.
|Thundershock||Pokémon, I Choose You!|
|Thunderbolt +||Showdown in Pewter City|
|Agility||Electric Shock Showdown|
|Quick Attack +||Electric Shock Showdown|
|Thunder||Showdown at Dark City|
|Double Edge||Friend and Foe Alike|
|Tackle -||The Double Trouble Header|
|Leer -||Hour of the Houndour|
|Iron Tail +||All Things Bright and Beautifly|
|Volt Tackle||May's Egg-Cellent Adventure!|
|Electro Ball +||Dancing With the Ducklett Trio|
|+ indicates this Pokémon used this move recently.*|
- indicates this Pokémon normally can't use this move.
- Rachael Lillis (original voice in some episodes of the English version of the Pokemon anime.)
- Ikue Ōtani (present- in both the Japanese and English-language versions of the Pokemon anime.)
- When Ash received Pikachu from Professor Oak, his Poké Ball had a lightning bolt on the top part.
- Because Pikachu doesn't like being inside his Poké Ball, it has only been seen a few times since the first episode. The first was against Brock when Pikachu was being attacked brutally by Onix and the second was in the episode Snow way out when Ash becomes worried about the safety of his Pokémon in the cave's freezing conditions. Both times Ash's attempted return of Pikachu was blocked, by Onix the first time and by Pikachu the second.
- Ash attempted to evolve Pikachu with the Thunder Stone after he lost to Lt. Surge's Raichu, but Pikachu chose not to evolve because he wanted to prove that he can defeat stronger Pokémon without evolving.
- Pikachu occasionally has acted as a responsible leader of the main cast's Pokémon, mainly Ash's Pokémon.
- In the season one episode "Showdown at Dark City", Pikachu displayed a strong fondness for ketchup. In fact, when the ketchup bottle he was carrying was smashed, Pikachu was seen crying over the smashed ketchup bottle. This could be an indication on how close Pikachu's relationship with Ash is, since his last name is phonetically similar to ketchup.
- In the Season One episode "Ash Catches a Pokémon", when Team Rocket was trying to steal Pikachu, Meowth accidentally says that Ash's Pikachu's power exceeds the power level he would possess as a Raichu.
- In Climbing the Tower of Success, a Thunder Stone was tossed to Ash, thus it almost landed on Pikachu which would cause him to evolve. However, Ash was scared about Pikachu evolving, so he prevented this, which contradicts to the time he offered Pikachu a Thunder Stone to evolve. The most likely reason is that Ash now knows Pikachu doesn't want to evolve (and likes keeping him the way he is and respects his wishes), which is supported in the Diamond and Pearl generation episode Pika and Goliath.
- Both Ash's Pikachu and Snorlax are evolved baby Pokémon but in that generation they are the first forms.
- Pikachu had a special event for the 4th Generation of Pokémon Games knowing the moves Pikachu had in Sinnoh League Victors.
- Ash's Pikachu is finally confirmed male in Where No Togepi Has Gone Before! after being hit by Togepi's Attract. This is also when Jessie's Yanmega was confirmed female.
- Pikachu seems to have a great dislike, or even hatred, against Team Rocket's Meowth. As after Meowth and his team got away from the failed rail road mission in Unova, Pikachu still exerted a lot of anger and Ash had to hold him down. While Meowth was in Ash's group, Pikachu was the one to always be suspicious of Meowth's loyalty. This could stem from the fact that every time Pikachu started to trust Meowth, Meowth then betrayed that same trust.
- Ash's Pikachu is the most recognizable Pokémon, therefore being the face of Pokémon.
- Some how for every region Ash has traveled through with Pikachu he has always been for the most part surpassed in power by another Pokémon that Ash catches and trains until they fully evolve or learn new moves.
- Beginning from Hoenn onward, every time Ash and Pikachu enter a new region, Pikachu has been exposed to high levels of electricity or magnetism, before or after arrival, and loses control of its own electricity, becomes confused, and runs away, forcing Ash to chase after it.
- This could explain why Pikachu's strength is "reset" each time they start a new reigon.
- Pikachu has had many moves over the seasons, but the amount it now actively uses has been lowered to only four.
- Pikachu is very fond of battling and takes part in almost all of Ash's Gym Battles. Pikachu has a great willingness of continuing to fight till the end, even if he's getting tired to continue.
- Despite Pikachu's absence from the Unova Dex and not being native to the Unova region, a Trainer's Pikachu can be seen in Castelia City, and another Pikachu is depicted on a billboard. Also, there are several Pikachu-shaped hedges in Striaton City.
- Pikachu is the only type Pokémon of Ash's. -
- Pikachu's hatred of being in a Poké Ball made him the last and hardest to be captured by Mewtwo.
- Pikachu is the only Pokémon in the anime to defeat two Legendary Pokémon without being a Legendary Pokémon himself. His first victory against a Legendary Pokémon was when he defeated Brandon's Regice and the second was when he knocked out Tobias' Latios, although the battle against Latios ended as a draw rather than a victory.
- Despite beating Legendaries, Pikachu lost to Trip's Snivy even though it doesn't have any battle experience.
- Pikachu was also the first of Ash's Pokémon to habitually disobey him. Primeape and Charizard would also follow suit and are better remembered for their disobedience than Pikachu.
- Dawn's Buneary shows romance for Pikachu, it is unknown that Pikachu feels the same.
- In one episode, Pikachu temporarily loses his memory and Team Rocket fills with lies, causing Pikachu to side with Team Rocket when they encounter Ash and Co. Although in this moment Ash tries to tell Pikachu the truth, Pikachu is more convinced by Team Rocket's lies.