Pikachu is Ash's best friend. Pikachu has always been there for Ash and also takes a leadership position for the team. He is curious, smart and friendly, but shares Ash's fondness for battling. One of his most noticeable features is his determination and unwillingness to give up whenever a situation gets tough. He is shown to be responsible with younger Pokémon, particularly Misty's Togepi, who he is often forced to shepherd out of danger by putting himself in it. Although stubborn at times, he obeys Ash's commands in battle and rarely leaves his side. He is also a constant target for Team Rocket. They try to capture him, but on the few occasions that they do, their plans are always thwarted by Ash and his friends. Even after getting out of their traps, avoiding capture, or that he wasn't part of their schemes, Pikachu also thwarts his enemies by attacking or getting rid of them using his Electric-type attacks, like his signature attack, Thunderbolt. He is very swift in battles as well. He can also imitate some Pokémon by making their face shapes.
Like his master, Pikachu shares Ash's love for science and technology; even if he cannot understand most of it.
Pikachu has close friendships with Ash's Pokémon that he had or has, with Ash's traveling companions and their Pokémon as well also some of their Pokémon are his best friends, other than his trainer.
In some episodes, Pikachu has a strong rivalry with other trainers' Raichu which is Pikachu's evolved form, who is much stronger than the latter and also responsible for injuring Pikachu in every first battle with the exception of both Volkner and Tierno's Raichu who appears as a calm, serious and a friendly Pokémon. In Sun and Moon series during the pancake race, it showed Pikachu wanted to defeat an Alolan Raichu. The prime example is when Lt. Surge's Raichu manage to overpower Pikachu with its abilities and also injures it in the process. This also carries to Sho's Raichu who also overpowers all of Pikachu's abilities such as his Iron Tail and Volt Tackle. Despite their overpowered prowess, Pikachu is able to withstand against them by using its speed and its tactics in battling in order to defeat them.
During the time when Pikachu was injured in each of the first battles against the trainer's Raichu, he was given the chance to evolve into a Raichu using a Thunder Stone but Pikachu often refuses. This trait is later shared by his best friend, Dawn's Piplup who also given the chance to evolve, but also refuses as he has an Everstone to prevent it.
They are each other's best friend, even though they had a rough start at first, they've been at each other's side no matter what. They would protect each other from trouble and would stand up for each other. A lot of people see that they're perfect partners. Pikachu has helped Ash break free from someone's control a couple times in there adventures and Ash has helped Pikachu do the samething plenty of times showing how strong there friendship is.
Kanto and Orange Islands
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 detested Ash at first, Ash demonstrated his willingness to sacrifice himself for Pikachu, and they quickly became friends. Pikachu became close friends with Misty and Brock. He was also good friends with the first two Pokémon that Ash caught, who he later released to be there with their own kind, and then became best friends with the Kanto starters and Misty's Togepi, who he helped to keep out of trouble from time to time. He is also good friends with other Pokémon that Ash caught along the way through their journey in Kanto. In one of Pikachu's gym battle, he was given the training to increase the strength of the electric sacs in his cheeks in order to beat the first Gym Leader, Brock. After his defeat in his battle against Lt. Surge's and his Raichu, he was given a choice to evolve but refused so he can prove he's strong without evolving. Pikachu had been in 5 out of the 8 of Ash's gym battles in Kanto and put a good effort in Indigo League, during which Ash ended in the top 16 when he lost to Ritchie.
After the league was over he, Ash, Misty and Brock went to the Orange Islands to get something for Professor Oak, which was the GS Ball, from Professor Ivy. When Brock decided to stay with Prof. Ivy, he found a new close friend in Tracey when another one of Team Rocket's scheme failed and landed them in one of the Islands. When Ash found out there's a league in the Orange Islands that's when Ash decided to take a detour to check out the Orange Archipelago to compete in the league there, with Misty and Tracey coming along. They travel through the islands with one of his new friend Lapras, whom Ash rescued from some boys who were abusing it. He released it as well when they were going back to Pallet town, traveling from one island to another. At one point Team Rocket's members, Butch and Cassidy used a Pokémon to turn him against Ash along with other Pokémon as well, however, they were foiled thanks to Ash using Pikachu to attack him while standing on the control box that set him and the others free. Later on, he befriended a Snorlax that was causing trouble at one of the Islands they visited. Pikachu was in two out of the four gym battles and was able to help Ash win the league after defeating Drake. Pikachu was surprised to see Brock back in Pallet town along with Ash and Misty. He battled against Gary's Umbreon later on, who was still an Eevee at the time, a battle that he lost.
When Ash heard of the Johto region he decided to go there with Misty and with Brock returning, Tracey stayed behind to become Professor Oak's assistant. Pikachu had his longtime friends along the ride for a while until Charizard left to train in Charicific Valley but it returned to help out in one of the gym battles and in the league. Squirtle went back to lead its gang again but came back to help out in the league and Bulbasaur went to Professor Oak's lab to keep the peace there. Pikachu came across some new best friends in the Johto starters and also with Phanpy after a rough start, a Pokémon Ash first raised as an egg. Pikachu has been in all of Ash's gym battles and was able to help a lot in the league, however, Ash ended in the top 8 when they lost to Harrison. Pikachu was bummed when Misty and Brock had to go back home and then decided to go with Ash to a new region, Hoenn when Ash decided to just be him while all his friends from Johto were left in the care of Professor Oak.
Hoenn and Battle Frontier
While on the boat to Hoenn, Team Rocket were also on board and stole Pikachu while he and Ash were sleeping. However, he ended getting separated with Meowth in a city where they meet some wild Pokémon whom Pikachu helped settle a feud that was going on between some of them. When Team Rocket tried to steal him again, Ash got there to save him but ended up in a giant magnet they had set to trap him, but they were stopped once again and Pikachu was safe. However, the next day, Pikachu ended up getting sick from being exposed to the magnet. 
Once Ash and Pikachu arrived in Littleroot Town, Ash called Professor Birch for help due to not having a Pokémon Center. While getting to the lab Professor Birch explained that Pikachu had an Electric build up which was very common for Electric-Type Pokémon to get. Once they got to Professor Birch's lab, they tried to get the extra Electricity out of Pikachu system but it was proven too powerful which caused an explosion and Pikachu ended up leaving due to being confused from the fever. Pikachu kept wondering but was found by Ash. He fell off the cliff while still being confused, although he was saved by Ash in the nick of time. They were then pulled up by Professor Birch and a new trainer named May, however, while Ash was climbing Pikachu bit Ash in the arm, but calmed down after realizing who he had just bitten. Team Rocket showed up which resulted them helping Pikachu get rid of his extra electricity, but he collapsed after sending them blasting off again. Pikachu got some rest and felt a lot of better with Ash being by his side till he got up.
Pikachu ended up getting a new close friend in May also he became best friends in her starter Pokémon, Torchic, after May decided to travel with Ash. Pikachu got another close friend in May's little brother Max and was happy to be reunited with Brock while getting two new best friends in the starters Ash and Brock caught, Treecko and Mudkip. Pikachu got some new close friends in the rest of the Pokémon Ash caught along the way.
Pikachu and everyone ended up meeting Team Magma and Team Aqua where they encountered them doing some bad stuff. They tried to stop their plans or watched to see what they were up to although there been times they got away along with them success at what they came for. Pikachu ended up seeing Misty again while helping her and everyone else out to foil a plot to overthrow a kingdom. Pikachu had to say goodbye to one his long time friend in Togetic, evolved from Misty's Togepi, when it decided to stay and protect the kingdom they just saved before having to say goodbye to Misty who had to return to Kanto.
When another one of Team Rocket's plan failed again when their robot blew up and because of it, Pikachu ended up getting amnesia from the explosion when he landed. Team Rocket used it to their advantage and they convinced him that they're his friends. However, Ash and everyone arrived but Pikachu couldn't remember them with Meowth telling him that they're bad guys, although Ash tried to tell Pikachu that it wasn't true and Pikachu wondered if he was telling the truth but thought it was a trick due to Meowth telling him that's he's a liar. With Pikachu turning away from Ash and everyone which showed that Team Rocket has fully turned Pikachu against his best friend, Ash, and close friends, Brock, Max and May. Pikachu got his memory back from either the explosion from the balloon, after trying to make their escape with Ash climbing up to get his best friend back, or when Ash protected him when they were falling from the sky and fell into a river.
Pikachu ended up getting possessed, due to Groudon asking for his help, from the Blue Orb that Team Magma had, which involved him and everyone else in Team Magma and Team Aqua's final operation. They were foiled with everyone helping out along with Lance, the champion of Kanto, and a little help from Team Rocket. Pikachu ended up being free of the Orb's control after they were stopped.
Pikachu was in 7 out of the 8 of Ash's gym battle and put a good effort in the league but Ash ended up in the top 8 again after losing to Tyson. After the league was over, he said goodbye to his close friends but ended up meeting Scott, the owner of Kanto Battle Frontier, while on their way home and he offered Ash a chance to compete which he said yes to. Pikachu got to reunite with his friends and then left with Ash, May, Max and Misty, who returned to Cerulean City and also with 3 members from Hoenn who came along while the other two stayed at the lab. Before they left, his friend Phanpy caught up with them and decided it wanted to travel again much to his happiness, who evolved into a Donphan later on, with Brock also catching up to them as well before leaving Pallet Town.
Pikachu got a new close friend in one of the Pokémon Ash caught, who followed him. He was in 3 out of the 7 of the Frontier battles that Ash had. After saying goodbye to May, Max and Brock again, they went home and met up with Gary again. He battled against Gary's Electivire and was defeated. Ash and Pikachu left for Sinnoh the next day, with Ash leaving his Pokémon at the lab but one of them sunk aboard the boat they were on and Ash let it stay with them.
When they arrived, Team Rocket tried to steal him again when Ash was talking to Professor Oak on the phone. However, Meowth used Fury Swipes on Wobbuffet, who returned the attack back using Counter, after they had a fallout, which resulted in the balloon blowing up which ended up with Pikachu falling into the forest somewhere and Team Rocket blasting off again. 
Pikachu was found by a new Trainer named Dawn and her partner Piplup. She wanted to catch him but found out he belonged to someone else. Team Rocket then found him, although he was aided by Dawn and her Piplup and they were successful at defeating them, he collapsed from exhaustion and was taken to a Pokémon Center to recover.
After recovering at the Pokémon Center, Dawn decided to take him to his Trainer, but they were found by Team Rocket again. However, Ash got there to save him in time and was reunited at last. He was happy to get a new close friend with the Pokémon Ash caught to help find him. After everything was resolved, they went to Professor Rowan's lab where Ash got his new clothes from his Mom. He was happy that Brock was back for their new adventure but was even happier when Dawn decided to travel with them thus getting a new close friend in Dawn while forming an unbreakable friendship with her Piplup.
Before they headed out, Ash was challenged to a 3 on 3 battle with Paul, the trainer Ash and Brock met earlier, but their battle ended in a draw. 
Pikachu ended up getting two new best friends in one of the starter Pokémon that Ash caught, a Turtwig and with the first Pokémon Dawn ever caught, a Buneary, who also had a crush on him. At one point, Pikachu gets another best friend in the starter Pokémon that Paul had, a Chimchar, which he abandoned after it didn't meet his standard and was very happy when Ash decided to take it in. Pikachu has a close friendship with one of the Pokémon Dawn traded for one of Ash's and the other two Pokémon Ash caught along the way.
In one battle with a trainer and his Raichu, he got injured pretty badly and while he was recovering Ash brought out the Thunder Stone he had kept since their battle with Lt. Surge. Ash told everyone his reasons for keeping it all this time and left Pikachu to decide if he wants to evolve or not. When everyone went to check up on him, he was gone with the stone missing as well leading everyone to think he evolved but they found him training while seeing he chose not to evolve once again. Once the training was done, they challenged the trainer and his Raichu to a rematch and won this time around.
Pikachu got to see his friend May again at some point in their journey when she came to Sinnoh for a big contest she, Dawn and Ash were going to be taking part in but had to say goodbye to her when the contest was over. There have been a couple of times he got to see Gary who helped them out and he with Ash, helped him out in return as well. Pikachu and everyone encountered Team Galactic a few times before they got involved in their final operation which they stopped with a lot of help from his trainer, friends, Team Rocket, Looker, Cynthia and the Legendary Lake Trio.
Pikachu was in 4 out of 8 of Ash's gym battle and did amazing in the league but Ash ended up in the Top 4 after losing to Tobias. After the league was over, he had to say goodbye to Dawn and his friend Piplup, who didn't want to say goodbye to anyone at all. After saying goodbye to Brock, they went back to Pallet Town where Ash's mother and all of his friends awaited them.
Pikachu came with Ash on a trip to Unova, but when they got there, they were ambushed by Team Rocket once again. However, during the confrontation, Zekrom appeared in a storm cloud, accidentally cancelling out Pikachu's Electric attacks, that was not known to Ash until he had his first battle with a rookie trainer name Trip.
Pikachu regained his Electric attacks after Zekrom appeared again and he stayed with Ash when he decided to travel around Unova. While walking and seeing the different Pokémon, he met Iris, after Ash mistook her for a Pokémon. Pikachu became close friends with Iris and Cilan along with forming a strong friendship with Iris's Axew and Cilan's Pansage. Along with getting new best friends in the Unova starters Ash caught Pikachu gets some new close friends with the other Pokémon Ash caught as well. Pikachu was a big help in 5 out of 8 of Ash's gym battles.
After Ash won all his badges they met Cynthia, the Sinnoh region champion, again and then befriended Meloetta, the Pokémon Ash helped while they were in Virbank City, after it got injured and when it followed Ash. Pikachu got to see Dawn and his friend Piplup while preparing for a tournament they were all going to enter in. After the tournament was over and Dawn left to go to Johto, they got involved in Team Rocket's operation Tempest where he and Ash got captured as hostages so Meloetta would do whatever they asked. However, Pikachu and Ash were able to get free from captive then he was able to help free Meloetta when he used a powerful Electro ball attack, thus putting an end to Team Rocket's plans with a lot of help from his trainer, Cilan, Cynthia, Iris, and Ridley, Meloetta's friend. When the crisis ended, they went to the Unova league where Pikachu put a good show but lost during the quarterfinals against Cameron, thus putting Ash in the top 8.
After the league was over, Pikachu along with his Trainer and friends went to see the white ruins of Reshiram. While going there, they met N and then met up with Looker again before meeting Team Plasma, who were working on the Pokémon control device. During their first encounter with Team Plasma Pikachu fell victim to their unperfected Pokémon control device, which was made during one of their experiments, but he was able to hear his trainer's voice thus setting him free from it. Pikachu along with his trainer and friends meet up with N again, who decided to traveled with him for a while. While in Virbank City, they came across a fair for his and Ash's home region, Kanto. During the festival, he and Ash remembered one of their longtime friend Charizard and Ash asked Professor Oak to send it to see it. He was happy when Ash decided to let Charizard be in his party for full-time again.
When N left the group, after finding out about his past with Team Plasma, they made their way to the white ruins where they met back up with N again but they fell into a hole when Ash tried to reason with him after taking the light stone containing a sleeping Reshiram from Cedric Juniper. Thanks to the efforts of N, Ash and all his other Pokémon with Pikachu helping out as well, they were able to get out of their predicament to help defend off Team Plasma, after Cedric, Cilan, Iris and Looker got captured by them. When Team Plasma was about to fire their perfected Pokémon control device at Ash's Pokémon, Ash was able to get everyone else to safety, by calling his Pokémon back into their Poké Ball, except for Pikachu, due to him not liking to go to his Poké Ball. Ash tried to get Pikachu away from it but was too late as he got hit by the device and was controlled again. Ash tried to get through to Pikachu but to no success, as he was completely under their control during which he got knocked unconscious from one of Pikachu's attack. Then N made a deal with them to set him free from their control which they agree to do thus setting him free from their control but he passed out from exhaustion, right after looking at his unconscious trainer feeling ashamed at what‘s he done. After he and Ash regained consciousness, they saw N's foster sisters come in, to rescue N before witnessing Reshiram awaking right before being placed under Team Plasma control, during which Looker, Iris, Cilan and Cedric were able to get free from there bands they were in.
When Team Plasma noticed them still trying to get in their way, he was about to be under their control again but Ash stepped in to protect him with Meowth helping him out as well. Ash told Pikachu to stay with Looker, Meowth, N and his fosters sisters so he wouldn't be controlled again when he decided to destroy the device on his own with Jessie and James coming along to draw there attention away from Ash. However seeing Ash in trouble Pikachu came out of hiding to help, not caring if he got controlled again, with Cilan, Iris and Meowth's help. Pikachu fired an Electro ball to destroy the device, however, he was hit by it again during the firing but the electricity from the attack helped him fight off the devices control. Through Iris, Cilan, Axew and Ash's encouragement, he was able to keep resisting much to the surprise of Team Plasma. Pikachu used his Thunderbolt on Reshiram, who was in the way of the device, to wake it up but he got hit by the device again. However, he kept going with Ash and Iris encourging him not to give up while saying he's got to stay strong. Pikachu was able to destroy the device with Reshiram's help thus setting all the Pokémon free which put an end to Team Plasma once and for all.
With their adventure in Unova done, they decided to take a detour to the Decolore Islands with Iris and Cilan coming along with them back to Kanto. They met up with Professor Oak, who was looking to catch a Pokémon. Although he did offer the plane ride back, they all declined to keep exploring. They met Alexa, a journalist from Kalos, there. Once they got to Kanto, he had to say goodbye to Axew, Cilan and Iris before heading back to Pallet Town with Ash and Alexa. Pikachu got to see his friends again in the lab and then decided to head to Kalos with Ash and Alexa the next day.
Once they arrived in Kalos, they had their hearts set on a Gym Battle but couldn't right then. He got new close friends in Clemont and Bonnie. Pikachu also got two new best friends in the starter Pokémon Ash caught and the Dedenne who followed them. Pikachu gets another close friend in Serena, who knew Ash back when they were children, along with getting close friends in the Pokémon that Ash caught in their journey. He also became best friends with Clemont and Serena's starter Pokémon.
Pikachu served as the leader of all of the Pikachu celebrities in the movie created by the Pikachu director, Frank who is very fond of all the wild Pikachu from the Pikachu village including Ash's. Pikachu plays the role as Super Pikachu which was also dubbed by Ash on the movie. Pikachu's stunt double when it flies down on the ground was Ash's Hawlucha who also wears a Super Pikachu costume. After watching Frank's movie creation, Pikachu was amazed about the movie he had created as well as the bloopers they have in behind the scenes.
At one point they met a mysterious Pokémon, nicknamed Squishy by Bonnie, who was being haunted by Team Flare and they ended up meeting them in person. Pikachu was in 5 out of 8 of Ash's gym battle and gave a superb display in the league but Ash ended up runner-up this time after losing to Alain.
Shortly after Team Flare and Lysandre began their assault on the city, Pikachu and Ash were hit by Celosia's Drapion's Confuse Ray which resulted Ash losing consciousness from the Confuse Ray effects. Although Pikachu tried to fight off the Confuse Ray while protecting an unconscious Ash from Team Flare but he also lost consciousness from it as well. He was captured and hung up in the air with restraints while still out unconscious at the time along with Ash and the rest of his Pokémon at the top of Prism Tower by Lysandre's behalf, as he intended to use him, Talonflame, Goodra, Hawlucha and Noivern as hostages for his two best friends, Ash and Greninja. Pikachu regained consciousness right after Ash did then look at horror of the destruction caused by Lysnadre plans along with seeing the Zygarde under there control before witnessing Squishy transform into Zygarde, also during that time is when his friends also regain consciousness, which shocked him that Squishy was a Zygarde this whole time. Despite not knowing the truth about Squishy sooner Pikachu helped Ash defended it when Lysandre tells him and his friends about how Squishy will be under there control as well. Pikachu became shocked and worried when Lysandre used the mini version of the Mega Evolution Energy Wave machine on Greninja and Ash so he can control them. However Pikachu was able to saved Ash by calling out to him which got through to him also it through to Greninja as well, just before both of them were about to give in to Lysnadre's control, much to his relief. Then they both used Bond Phenomenon to break free from there restraints also thanks to Alain's Charizard, Pikachu and the other Pokémon were set free and were ready to battle.
Before heading back to Kanto, Pikachu had to say goodbye to to his friends before saying goodbye Serena, Clemont and Bonnie. Pikachu and Ash arrived back at night with Ash opening the door to his house and telling his mother that he's home.
Like the previous regions, Pikachu was the only Pokémon that Ash brought with him to the Alola region. The two friends went on vacation there, while having a great time riding on a Sharpedo. After they got chased by Bewear they ended up at the Pokémon school and when Kiawe got into a fight with the members of Team Skull, Ash and Pikachu rushed to the scene to help him finish off Team Skull's Zubat with Thunderbolt.
To finish the battle, Pikachu and Ash witnessed Kiawe and his Turtonator use their Z-Move Inferno Overdrive. After Ash received a Z-Ring of his own and attended the Pokémon School, Pikachu was challenged to a battle by Tapu Koko. In the midst of the battle, Tapu Koko taught Pikachu and Ash how to use the Electrium Z crystal and the move Gigavolt Havoc before the Guardian deity flew away.
After the battle with Tapu Koko, he gets new close friends in Ash's classmates, Kiawe, Lana, Lillie, Mallow and Sophocles. Pikachu ended getting new best friends in the first three Pokémon Ash's caught, two being starter Pokémon Rowlet and Litten, while the other one being Rockruff that Pikachu ended up bonding really well with. Pikachu gets two other best friends in Lana's Popplio and Sophocles' Togedemaru.
Ash used Pikachu and Rowlet in the Verdant Cavern Trial Challenge and the pair made quick work of Yungoos and Gumshoos. As they went up against the Totem Gumshoos, they find it to be quite a strong opponent as it took out Rowlet with Fling as the Grass Quill Pokémon tried to defend Pikachu. Using Pikachu's speed and Totem Gumshoos' Sand Attack; they were able to beat the Totem Pokémon earning Ash the Normalium Z-Crystal.
Pikachu befriends a Cosmog, nicknamed Nebby, who Ash decided to take care off after having a dream with Ash where he promises Solgaleo and Lunala that he would take care of it until they return it to its proper home.
The Electric Tale of Pikachu
- Main article: Ash's Pikachu (ETP)
Ash & Pikachu
- Main article: Ash's Pikachu (A&P)
Diamond & Pearl
- Main article: Ash's Pikachu (D&P)
|Thunder Shock||Pokémon - I Choose You!|
|Thunderbolt +||Showdown in Pewter City|
|Agility||Electric Shock Showdown|
|Quick Attack +||Electric Shock Showdown|
|Thunder||Abra and the Psychic Showdown|
|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.
|Gigavolt Havoc +||The Guardian's Challenge!|
|Breakneck Blitz +||Trial and Tribulation!|
|10,000,000 Volt Thunderbolt||SM054|
|+ indicates this Pokémon used this move recently.*|
- indicates this Pokémon normally can't use this move.
- Electric Slam
- Rocket Punch
- Thunder Armor
- Quick-Iron Tail
- Swift-Quick Attack
- Thunder Tackle
- Volt Tail
- Counter Shield
- Thunder Whirlpool
- Hydro Volt Tackle
- Electro Bolt
- Massive Electro Ball
- Electro Iron Tail
- Draco Meteor Climb
- Aura Sphere Climb
- Electrified Dragon Pulse
- Ikue Ōtani (Japanese; in both the Japanese and English-language versions of the Pokémon anime)
- Rachael Lillis (English; in some episodes of the English version of the Pokémon anime)
- Kayzie Rogers (English; Pokémon Learning League)
- Claudia Motta (Spanish)
- Sabine Bohlmann (German)
- Pikachu is the only one of Ash's Pokémon to appear in every Pokémon episode and movie.
- Pikachu is Ash's only Electric-type Pokémon and was the only Electric-type owned by a main character in the anime until the capture of Dawn's Pachirisu.
- 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.
- Pikachu had a chubby appearance in the beginning of the series but lost the weight for a more slender appearance from Generation II onward.
- Ash gave Pikachu a choice to evolve with the Thunder Stone after Pikachu lost to Lt. Surge's Raichu, but Pikachu chose not to evolve because he wanted to prove that he could defeat stronger Pokémon without evolving. This makes him the first of Ash's Pokémon to choose not to evolve.
- 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.
- The animation for the Japanese ending song "Pikachu's Song" in the XYZ series features Pikachu dancing around huge ketchup bottles, reaffirming his fondness for it.
- 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 and in the Pokémon X and Y generation episode The Cave of Trials.
- Both Ash's Pikachu and Snorlax are evolved baby Pokémon, but in the generation that they're obtained, they are just the first forms.
- There was a special event for Pikachu in Generation IV. The event Pikachu knew the moves that Ash's Pikachu had in Sinnoh League Victors.
- 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 main face of Pokémon.
- Somehow, 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 his own electricity, becomes confused, and runs away, forcing Ash to chase after him.
- This could explain why Pikachu's strength is "reset" each time they go to a new region, with the exception of Kalos and Alola.
- Pikachu has had many moves over the seasons, but the amount it now actively uses has been lowered to only four, to be accurate with the games.
- Pikachu's hatred of being in a Poké Ball made him the last and hardest to be captured by Mewtwo in the Pokémon movie Pokémon the First Movie.
- 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.
- Like the Diamond & Pearl series, Pikachu didn't learn any moves in the XY series.
- Pikachu seems to have his own language when referring to certain people or things. He often refers to Ash as "Pika-pi" because it sounds almost identical to his Japanese name, Satoshi. This also applies to Misty's Togepi who often calls Togepi as "Pipi-pi" and Misty who calls her as "Pikachu-pi" almost referring to her Japanese name as Kasumi. He also refers to Dawn as "Pikaka", partially referring to her Japanese name of Hikari.
- On the UK quiz show "Think Tank", it was incorrectly stated by a member of the Think Tank that Pikachu was the first Pokémon that Ash caught when in reality, Ash was given Pikachu as his starter Pokémon and the first one he caught was Caterpie.
- Pikachu has been captured and used as a hostage for almost every villainous organization in each region he's been to. Also, Pikachu is the first of Ash's Pokémon to be used for multiple villainous organization's plans.
- Team Rocket has captured Pikachu for their schemes in different regions, but they were thwarted a lot of times by him even if he wasn't part of their plans. Sometimes, he was captured with another Pokémon as part of their schemes. There were times he was captured for their schemes or so he wouldn't get in their way with his trainer. So far, Team Rocket has only used Pikachu once as a hostage for another Pokémon.
- Team Magma captured Pikachu because he had something they wanted, inside his body.
- Team Galactic only captured Pikachu so he wouldn't get in their way.
- Team Plasma had Pikachu captured, controlled, as part of their scheme.
- Team Flare held Pikachu hostage for his trainer and for one of his teammates.
- Team Aqua is the only villainous organization by far to not have captured Pikachu or used him as a hostage for any reason.
- ^ DP142: Where No Togepi Has Gone Before!, Pikachu gets hit by a female Togepi's Attract
- ^ JE158: Hoenn Alone!
- ^ AG001: Get the Show on the Road!
- ^ DP001: Following A Maiden's Voyage!
- ^ DP002: Two Degrees of Separation!
- ^ DP003: When Pokémon Worlds Collide!
- ^ BW001: In the Shadow of Zekrom!
- ^ BW002: Enter Iris and Axew!
- ^ XY078: Lights! Camera! Pika!
- ^ XY132: A Towering Takeover!
- ^ XY133: Coming Apart at the Dreams!
- ^ XY137: Battling with a Clean Slate!
- ^ XY140: Till We Compete Again!
- ^ SM001: Alola to New Adventure!
- ^ SM009: To Top a Totem!