Pikachu

"Pika, pika!"

- Pikachu's famous expression

Pikachu (Japanese: ピカチュウ, Pikachu) is the iconic mascot of the Pokémon franchise, serving as the main animal protagonist and the deuteragonist of the Pokémon anime series, and one of the eight protagonists of the ''Subspace Emissary. ''It is an Electric-type Pokemon that resembles a mouse.

Pikachu evolves from Pichu by leveling up with max happiness. Pikachu evolves into Raichu if given a Thunder Stone.

It is voiced by Ikue Ohtani in most of its appearances, particularly its male version and in Pokémon the Movie: I Choose You!, he is voiced by Kate Bristol (best known as Kisa Sohma) as speaking.

In Detective Pikachu, his "normal" speaking voice is voiced by Ryan Reynolds, who also played Hal Jordan and Deadpool, while his "Pokemon Speak" speaking voice is provided by Ikue Ohtani.

Biology
Pikachu is a short, chubby rodent Pokémon. It is covered in yellow fur, and its ears are long and pointed with black tips. It has a small mouth, brown eyes, and two red circles on its cheeks. There are pouches inside its cheeks where it stores electricity. Its forearms are short, with five fingers on each paw, and its feet have three toes. It has two brown stripes on its back, and its tail is in the shape of a lightning bolt with a patch of brown fur at the base. A female will have a V-shaped heart notch at the end of its tail, which looks like the top of a heart. It is classified as a quadruped, but it has been known to stand and walk on its hind legs.

In "Pikachu's Goodbye", it is shown that Pikachu sometimes travel in groups. It raises its tail to check its surroundings, and is occasionally struck by lightning in this position. Living in forested areas, Pikachu is found foraging for berries it roasts with electricity to make them tender enough to eat. It has been observed eating and sometimes destroying telephone poles, wires, and other electronic equipment.

Pikachu is able to release electric discharges of varying intensity. Pikachu has been known to build up energy in its glands, and will need to discharge to avoid complications. It is also able to release energy through its tail, which acts as a grounding rod, as well as recharging fellow Pikachu with electric shocks. Pikachu can also electrify itself to use its signature move, Volt Tackle. When threatened, it looses electric charges from its sacs, and a group can build and cause lightning storms. It is found mostly in forests, where a sure sign that Pikachu inhabits a location is patches of burnt grass.

Ash's Pikachu (anime)
In the anime, Ash got a Pikachu from Professor Oak as his starter Pokémon when the other three were already taken. At first Pikachu didn't get along with his Trainer, but he gradually warmed up to him and they have been great friends ever since. Together, they go on many adventures with many friends. Pikachu hates being inside his Poké Ball

A criminal organisation named Team Rocket consisting of Jessie, James and the Scratch Cat Pokémon Meowth are constantly trying to steal him in almost every episode as they were impressed by his skills in their first encounter with he and Ash. However, Team Rocket always fails and Pikachu often sends them flying with a Thunderbolt.

Pikachu is appear in every episode in the main series along with Ash.

This Pikachu Ash owned is confirmed to be a male due to the gender different that female a Pikachu had heart-shaped tail.

Pikachu (Super Smash Bros. series)
Pikachu has appeared in every Smash Bros. game. In Super Smash Bros. Brawl, he knows some very powerful attacks. His Final Smash is called "Volt Tackle", and it consists of it turning into a ball of electricity and zooming across the stage at a high speed, doing damage to any opponent it touches.

Prior two of its female counterparts’ appearances in Ultimate, namely based on Moon (Sun & Moon female protagonist) and Libre (known in Tekken/Soul-based fighting game Pokkén), the default gender of playable Pikachu in all of its appearances are mostly males. This makes Pikachu being one of the two Pokémon fighters alongside Pokémon Trainer (original Kantonian ones) to have their different genders as an “alternate costume”.

In the World of Light Sonic and Pikachu were running from Galeems beams of light but failed and got imprisoned by Galeem. After being defeated Pikachu became a playable character.

Pokken Tournament
Pikachu is a playable character in the game.

Trivia

 * Pikachu is one of the original 151 Pokémon in the series. Its Pokédex number is 25, which is coincidentally similar to Meowth's Pokédex number, which is the same but backwards.
 * Niue released a one-dollar coin featuring Pikachu as part of a commemorative promotion for the Pokémon franchise, with Pikachu on one side and the nation's coat of arms on the other.
 * Pikachu and its evolved form share their species name with Rattata, Raticate, Sandshrew, and Sandslash. They are all known as the Mouse Pokémon.
 * Veronica Taylor, the voice actress who voiced Ash in the first eight seasons of the anime, has stated that Pikachu is her favorite Pokémon.
 * In 2008, Japanese researchers discovered a new protein that helps carry electrical impulses from the eyes to the brain and named it pikachurin. According to the researchers, the decision was based on both the Pokémon and protein possessing "lightning-fast moves and shocking electric effects".
 * There have been three Pikachu balloons in the Macy's Thanksgiving Day Parade. The first, known as the "Flying Pikachu", was flown from 2001 through 2005. It was used in a morning rush hour test of wind conditions in Times Square after an accident involving an M&amp;M's balloon in the 2005 parade and made its farewell appearance at the Party of the Decade in August 2006, in New York City's Bryant Park. The second version debuted in the 2006 parade, features glowing cheeks, and chases a Poké Ball balloon. The third one, introduced for the 2014 parade, has Pikachu wearing a green scarf and holding a small Pikachu shaped snowman.
 * Pikachu is one of fourteen Pokémon that one can collect foreign Pokédex entries for in Pokémon Diamond and Pearl.
 * The earliest depictions of Pikachu had differently-colored bellies, most notably the sprites for Pokémon Red, Green, and Blue, as well as the international Red and Blue.
 * Pikachu is the only core series starter Pokémon with a pre-evolved form, though Pichu was not available in Pokémon Yellow.
 * According to A Sneak Peek at Pokémon, Pikachu can deliver a constant current of 1000 amperes.
 * As of Generation V, Pikachu has the most event-exclusive moves available to it.
 * In the Japanese Pokémon Stadium, Pikachu is the only Pokémon that can be used in battle that is not fully evolved.
 * In Pokémon Yellow, X and Y, Omega Ruby and Alpha Sapphire, and Sun and Moon, Pikachu uses its cry from the anime as voiced by Ikue Ohtani. Pikachu is the only Pokémon that uses its anime voice in any core series game.
 * If the starter Pikachu from Yellow is transferred to Pokémon Stadium or Stadium 2, it will also use its anime voice.
 * Black, White, Black 2, and White 2 are the only core series handheld games in which Pikachu is not available in some way.
 * It was said Pikachu was the most popular pokemon until in 2016 it reveals that Greninja was the top number.

Origin
Pikachu has physical aspects of several species of rodents, and its species name suggests that it is based on a mouse (although is still arguable as it's sometimes said to be a cat). It is not particularly similar to the pika despite its name, but its long ears do resemble those of other members of Lagomorpha. The rodent that Pikachu most resembles is the Viscacha, a type of chinchilla that lives in the desert.

Name Origin
Pikachu is a combination of ピカピカ pikapika (onomatopoeia for sparkle) and チューチュー chūchū (the sound of squeaking). Pikachu was designed by Atsuko Nishida, a member of the core design team at Game Freak.