Raichu is the evolved form of Pikachu and has orange fur, unlike Pikachu's yellow fur. In order for a Pikachu to evolve into a Raichu, it must use a Thunderstone. It can hold much more electricity in its cheeks. In the Pokémon anime, Gym Leader Lt. Surge's Raichu has a battle with Ash's Pikachu. At first, Raichu wins, but Pikachu beats it in a rematch.