Over two decades since its creation, the Pokemon franchise's little, yellow electric mouse mascot is still one of the most recognizable characters in all of pop culture. In fact, he's commonly referred to as Japan's Mickey Mouse. Even if you've never played a Pokemon game or watched a single episode of the long-running anime series in your life, you know who Pikachu is. You'll also know who Ash's Pikachu is. Ash, or Satoshi as he's known in Japan, has been the show's protagonist since 1997, and Pikachu has been perched on his shoulder ever since the 10-year old trainer departed from Pallet Town to become the very best, like no one ever was.

Pikachu wasn't always destined to become the icon he so quickly turned into, though. Clefairy was the one that GameFreak and Nintendo had originally lined up as franchise's talisman, but was swapped out for the more gender-neutral looking Pikachu to appeal to both girls and boys. Though Pikachu's core design has remained largely unchanged since then, fans have noticed the Pokemon is much trimmer these days. It's also had a baby pre-evolution added to its line. A new form of Raichu and a female Pikachu have also been discovered to have more rounded tails than their male counterparts. (This latter point finally put to bed confusion over the gender of Ash's Pikachu.) Throughout all of this, Ash and Pikachu's bond has remained tight.

20 PIKACHU ONCE SPOKE ENGLISH

Pokemon The Movie: I Choose You Pikachu

Pokemon and humans have always been able to understand each other without speaking the same language. Famously, with a few special exceptions, pocket monsters' only form of communication is through repeating their own names in different tones of voice, and Ash's Pikachu is no exception. At least, he wasn't, until Pokemon The Movie: I Choose You! was released in 2017.

In what was explained by Pikachu's English voice actor, Kate Bristol as a "dream sequence," Pikachu sorrowfully talks to a badly injured Ash in human-speak. The only plus side to this unsettling moment are the funny videos of movie-goers' WTF reactions that surfaced online when the film debuted in U.S cinemas.

19 PIKACHU JOINED TEAM ROCKET

Ash has been through many travelling buddies and encountered many nefarious characters during his journey around the Pokemon world. Other than Pikachu, the only constant in his life are the bumbling Team Rocket grunts, Jessie, James and their talking Meowth, who were obsessed with capturing Ash's BFF for years.

Though they were sworn enemies at the time, in the episode "A Scare To Remember," Team Rocket finally got their wish when a bump on the head caused an amnesiac Pikachu to join his trainer's rivals. Disappointingly for Meowth, Pikachu's moral fiber remained, and he never fully turned to the dark side.

18 PIKACHU WAS DESTINED TO REBEL

Pikachu

Takeshi Shudo, the Pokemon anime's first head writer, had some wild plans for the series that never came to fruition. As well as planning to hide Celebi inside the GS Ball and introducing Ash's absent dad, he also had an ending for the show in mind -- and it's super dark, much like the manga adaptations.

Pokemon has always been criticized for glorifying animal cruelty, and Shudo wanted the battling creatures to realize this too. His endgame involved a Pokemon rebellion against their human slavers with none other than the franchise's own mascot leading the charge. Meanwhile, Ash would have a crisis of conscience and abandon his ambition to become a Pokemon Master.

17 PIKACHU'S MORTALITY

Ash and Pikachu are so close that they would -- as we've often seen -- lay down their lives for one another. In Pokemon The First Movie: Mewtwo Strikes Back, Ash does the whole "taking a bullet" thing for his buddy, while Pikachu returns the favor in the series; refusing to leave Ash to freeze alone while trapped in a storm in "Snow Way Out."

Things got even hairier for Pikachu in "Get This Show On The Road," when he becomes so gravely ill that Ash is informed there's a risk he could "explode" if he doesn't get better. The young boy is understandably horrified. After all, we know from the graveyard in Pokemon Tower that there are some injuries Pokemon don't recover from.

16 PIKACHU ON A WHAT NOW..?

TOYOTA Pikachu Car

One measure of a property's success is the diverseness of its merchandise, and even though the Pokemon "craze" has ended, its bankability hasn't. Just like Hello Kitty or an Avenger, you slap Pikachu's face on just about anything and it will sell. Want proof? You can buy everything from officially branded children's vitamins to toilet roll holders to cars.

And if the official merch doesn't quite float your weird boat enough, how about a Pikachi ski mask, a Pikachu diaper or a Pikachu adult toy? (The last one comes as part of a set with the three Kanto starters, too.) For the morbid, Taxidermist Krysten Newby will even turn your dearly departed pet mouse into a real-life, frozen version of the eponymous character.

15 PIKACHU IS OVER (AND UNDER) POWERED

Pikachu

The reason that Team Rocket has made it a lifelong mission to catch Ash's Pikachu is because they think he's unnaturally strong, making him a great prize for their leader. Though Pikachu refuses to evolve to his stronger form, his incredible power has been demonstrated in his victories over Legendary and Mega-Evolved Pokemon.

If the anime series obeyed the natural laws of time, Pikachu's years at Ash's side would make him at least close to the maximum Level 100 by now; and yet, with the start of each new season, Pikachu repeatedly gets beaten by much weaker opponents. The only way to explain this huge inconsistency is that each new season effectively reboots everything, including Pikachu's experience points, to keep things interesting.

14 DETECTIVE PIKACHU'S MYSTERIOUS PAST

Detective Pikachu

The Detective Pikachu world is sort of an Elseworlds universe in which normal franchise rules can be creatively played around with, which is how we've ended up with a grizzled, hardboiled detective version of the normally cute and cuddly Pikachu. In this world, Detective Pikachu is also the only Pokemon capable of speaking to his human companion, Tim.

How did this curious feat come about? It's deliberately left unclear. All we know is that the coffee connoisseur's memories are hazy prior to an accident, leading fans to speculate that he doesn't remember possibly being human once, or that he's a human consciousness trapped in a Pikachu's body, as the result of a mad science experiment.

13 PIKACHU'S SHOCKS ARE SUPER STRONG

Pokemon Pikachu attacking

As we've already covered, Pikachu's power levels are all over the place, depending on where you are in the anime series or movies. His most well-known go-to moves -- Thunderbolt, Volt Tackle and Iron Tail -- either pack a huge punch or fail miserably. It's the former in Sun & Moon when his first use of Gigavolt Havoc is strong enough to shatter Ash's Electrium-Z crystal.

Also in Sun & Moon, the episode "10,000,000 Reasons To Fight!" gives Pikachu's old Thunderbolt attack a major boost. While battling anti-hero Gladion, Ash pulls out a new Z-Move: the 10,000,000 Volt Thunderbolt. As you'd expect, Gladion's strange Ultra Beast takes a (literally) shocking pounding from it.

12 PIKACHU CAN MAKE YOU ILL

Pikachu

Okay, not Pikachu the Pokemon -- Pikachurin, named after the famous Pokemon. The retinal protein was discovered by Japanese scientists in 2008 at the Department of Developmental Biology at Osaka's Bioscience Institute. It can be found in a nasty degenerative disease called Congenital Muscular Dystrophies, a birth defect that can cause seizures and learning disabilities.

The name was chosen because of protein's characteristics -- fast moving and fast acting -- reminded the scientists of Pikachu. Clearly the scientific community is nerdier than we ever thought possible, as a cancerous protein was named after Pokemon by American scientists in 2005, which annoyed Nintendo enough to threaten them with legal action.

11 PIKACHU HAS FANATIC FANS

The release of the Sun & Moon games in 2016 marked the first time Nintendo ever translated any of its titles into Mandarin, following years of letters and petitions from players in China, Taiwan and Hong Kong. However, the new localization came with some unexpected consequences -- including a name change for Pikachu.

Because Nintendo had chosen Mandarin over Cantonese, the more commonly spoken of the two Chinese languages, the new spelling of Pikachu's new name sounded subtly but noticeably different when read to what fans were used to. Players in Hong Kong became so enraged by this change to the flagship character they formed a 6,000-strong group to protest it. Nintendo told them to just ignore the new version.

10 PIKACHU IS REALLY BIG FOR A MOUSE

The fastest way to ruin everything you know and love about Pokemon is to take a look through the Pokedex. There, you'll discover how many ghost Pokemon have a habit of taking children, how many Pokemon would sooner eat than befriend one another and how freakishly big or small your party members actually are.

Among those surprising statistics is Pikachu. When you see him crouched on Ash's shoulder in the anime, he looks like a cute, oversized hamster, right? Well, according to the Pokedex, in-game Pikachus are 1'4" big. If one of those actually sat on your shoulder, you'd topple over. It's uncomfortably large for a monster supposedly based on a mouse.

9 PIKACHU HATES MEOWTH

Anime Meowth-fighting-in-Pokemon-TV-show

Seeing as how they've been adversaries for so long, it's not surprising that Pikachu isn't exactly Team Rocket's No. 1 fan. This is especially true after all their nefarious plots targeting Pikachu specifically. However, even when they were still hot on Ash and Pikachu's tail in the show, Jessie, James and Meowth were little more than comedy villains.

Their foolish shenanigans haven't stopped Pikachu from developing a hatred of Meowth in particular that runs pretty deep, though. Whenever Meowth acts duplicitously, Pikachu is usually the one most angered by it, with Ash sometimes having to coax him down from his fits of rage to stop to his buddy from blasting the talking cat off for good.

8 PIKACHU'S TERRIFYING TEMPER

Pikachu

For more proof of Pikachu's disdain for Team Rocket's "Scratch Cat" Pokemon, look no further than the Best Wishes series' "Battle For The Underground" two-parter. In the second part, a typical betrayal of trust from Meowth doesn't concern Ash much, but sends Pikachu on an all-out rampage, throwing everything he's got at him.

This isn't out of character for Pikachu, either. Though he's beloved by fans everywhere as an adorable plaything, Ash's Pikachu can swing from docility to fury in a matter of minutes. When they first met one another, Pikachu hated Ash and refused to do anything he said. Even since becoming friends, Ash has probably suffered permanent brain damage from Pikachu's continuous electric shocks.

7 PIKACHU IS ALWAYS TAKEN

Pikachu

Team Rocket aren't the only ones with eyes for the electric mouse. Ash's Pikachu has been prime bait for just about every shady group in Pokemon. Sometimes these abductions are motivated by Pikachu being needed for a sinister plot, like for Team Rocket's many world-domination schemes or for Team Plasma's manipulations.

Other times these evil organizations, like Team Flare, use Pikachu for hostage negotiations to get something else they want, usually to do with a new member of Ash's crew. But sometimes Pikachu's capture is about taking another piece off the board -- he does have a reputation for being over-powered, after all. So far, only Team Aqua have shown no interest in him.

6 PIKACHU'S PAST IS UNKNOWN

Ash meets Pikachu

We don't tend to think about what a Pokemon's life was like before being caught and adopted into their trainer's team -- or just sent to their PC box to become another number in their Pokedex. Pikachu is often mistakenly thought of as the first Pokemon Ash ever caught, but he was actually given to Ash by Professor Oak. (Caterpie was Ash's first catch.)

Pikachu was very resistant to joining Ash on his journey at first, which makes us curious about where he got this bad attitude from. Where did Professor Oak get Pikachu from? Did he have a previous owner? Pichu, Pikachu's pre-evolution, evolves through happiness, so maybe Pikachu's antipathy for Ash was rooted in him missing his previous trainer.

5 PIKACHU IS AFRAID OF POKEBALLS

Once a Pokemon is caught, it's traditionally kept inside its Pokeball for the convenience of its trainer. Not so much for Pikachu. Pikachu not only prefers to roam free by Ash's side, he downright refuses to get anywhere near a ball. This has proven to be a real problem for Ash at times because, as well as making travel easier, Pokeballs sustain an injured Pokemon until they can be healed.

In the aforementioned, "Snow Way Out," Pikachu would rather freeze than be balled up, and in Mewtwo Strikes Back, Pikachu becomes very distressed when Mewtwo's Pokeballs come after him. These extreme reactions make it seem like less of a preference and more of a phobia.

4 PIKACHU'S IMPOSTER

Mimikyu

When the Ghost/Fairy-Type Pokemon, Mimikyu was introduced in the Sun & Moon games, fans immediately fell in love with the creepy little guy. Its real appearance is unknown as it uses a crude- looking Pikachu costume to disguise itself -- doubling its appeal by association.

However, when the Alolan Pokemon debuted in the anime series, fans saw a different, more ghostly side to it. Meowth's encounter with Mimikyu nearly resulted in his untimely end for trying to peek under its costume, and when the imposter Pikachu lays eyes on Ash's real one, it flies into a rage, which Meowth explains is because it draws power from hatred -- and it hates Pikachu.

3 PIKACHU GETS BRAINWASHED A LOT

Pikachu brainwashed

At this point, Pikachu has suffered so many mental scrubbings that it's amazing he can still function properly. Brainwashing has become a favorite tactic of Team Rocket, but other Pokemon have turned Pikachu into a puppet as well. He's been turned into a drooling zombie by Malamar and turned against Ash by Butch and Cassidy's Drowzee.

In the worst instance, Kyogre's Blue Orb fused itself with him, transforming not only his mind but also his body. Under the Orb's control, the cute little critter developed red, glowing eyes and weird red symbols covered his body. In this state, Pikachu's temper was relentless, causing him to indiscriminately attack anyone and everyone until Kyogre was defeated.

2 PIKACHU GOT PORYGON BANNED

Though it's not exactly his fault, Pikachu is responsible for getting another Pokemon axed from the show. One of the few episode of Pokemon to have ever been banned is "Electric Soldier Porygon," which infamously induced seizures in a number of viewers from a sequence showing flashing red and blue lights when it aired in Japan.

It was pulled from TV schedules around the world and has never been re-aired or released on home video since. As a result, the titular Porygon and all of its evolutions were also pulled from the anime, despite the fact that Pikachu was the cause of the flashing. But, being the mascot of a multi-million dollar franchise gives you a lot of star power.

1 PIKACHU HAD A NICKNAME

Patrick Steward as Locutus of Borg in Star Trek the Next Generation

In the anime, Ash never officially gives his Pokemon nicknames like other trainers do, probably so that viewers can better remember their proper names. This isn't the case in The Electric Tale of Pikachu manga, which was loosely based on the anime. The mature content of this version had to be heavily censored for international release by Viz Media.

Misty's lack of clothing had to be altered in some panels, but evidence of the novelization's adult themes remained in Ash's nickname choices for his team, like "Felix the Caterpie," a reference to Felix the Cat. Pikachu's was more wholesome, however; christened "Jean Luc Pikachu" after the Star Trek: The Next Generation captain. It's a shame it didn't stick.