Who is Raichu?
Raichu is an electric mouse Pokemon.
And?
Raichu is the evolved form of Pikachu.
Why Raichu?
Pikachu is probably one of the most-recognized Pokemon in existence. I don't think enough attention is given to its clearly superior evolved form. If you watched the Pokemon TV show when it first came out you might have seen the episode where Pikachu battles a Raichu. He gets rocked at first but then comes back later after refusing to evolve into Raichu himself and beats down the enemy Raichu. This episode sent a message to all viewers that Pikachu has the ability to be better than Raichu because of it's speed/mobility and general cuteness. Also, most of the Pokemon TV show focuses on how awesome Pikachu is. For the most part they completely disregard Raichu. In my opinion, Raichu is better because he looks more elegant and doesn't have as annoying a voice as Pikachu does. Also, he is more powerful.