Raichu made its appearance in Electric Shock Showdown where it was responsible for brutally defeating many opponents, as the Pokémon Center started to get crowded. This happened before Ash entered the Vermilion City Gym. Later during Ash's arrival, Lt. Surge sends it out to him and his friends. Lt. Surge laughed at Ash for not evolving Pikachu, thinking evolved Pokémon are always better. This infuriated him and made Pikachu, also infuriated, want to battle Raichu.
In the battle, both sides start of with ThunderShock but Raichu's turns out to be powerful, which weakened Pikachu drastically. Raichu easily defeated Pikachu with a combination of Mega Punch and Mega Kick.
Ash returned to the gym for a rematch after Pikachu was healed. He ignored Lt. Surge's advice on evolving Pikachu into a Raichu. In the rematch, Raichu was able to hit Pikachu with Body Slam but Pikachu was able to use two new attacks, Agility and Quick Attack, which were both learned before the rematch, before being finished off. As Raichu evolved too fast, it never learned any speed attacks. Pikachu took advantage of this by using his speed attacks to confuse Raichu. Lt. Surge decided to cancel them by having Raichu Thunderbolt the field. However, Pikachu dodged it by using his tail. When Raichu was about to use Thunderbolt again, it ran out of electricity which gave Pikachu the upper hand. Pikachu finished off Raichu with his tail attack before Raichu made full contact with Take Down. As Ash eventually defeated Lt. Surge in a rematch, it proved to him that evolved Pokémon are not always better.
Raichu was seen again in a flashback in Pikachu's Goodbye when Ash was recalling the fun times he had with Pikachu, and in another one in Bad to the Bone, where Raichu was defeated in a Gym battle by Otoshi's Marowak.
Both Raichu and Lt. Surge reappeared in Pika and Goliath! in a flashback.
Personality and characteristics
Raichu's attitude towards Ash's Pikachu almost completely mirrors Lt. Surge's attitude toward Ash. When they first meet Raichu, it doesn't have a high opinion of Pikachu. However, after being defeated, Raichu grows to respect Pikachu.
A † shows that the move was used recently, unless all moves fit this case or there are fewer than five known moves.
In the games
Raichu appears as Lt. Surge's Pokémon in the player's Gym battle against him in all games he appears in. In Pokémon Yellow, it is his only Pokémon, much as in the anime. In other games it is not his only Pokémon, but it is always present. Lt. Surge's Pikachu that he has in the games is also shown below, since Surge said in the anime that he obtained his Raichu as a Pikachu.
