Raichu's FireRed and Sun Pokédex entries reference a 1903 documentary film called Electrocuting an Elephant by Thomas Edison.
Several Pokédex entries claim Raichu can discharge up to 100,000 volts. However, its Stadium entry claims it can only discharge up to 10,000 volts. This is likely a translation error due to the way numbers are read in Japanese, where 100,000 literally reads "ten ten-thousands".
Although Pikachu is the starter of Pokémon Yellow, it is not possible to directly evolve it into Raichu in the game, and must be traded in from Red and Blue. This inability to evolve Pikachu is a reference to Ash's Pikachu in the anime.
