Pikachu originally had an evolution called Gorochu, complete with fangs and horns

The Pokemon news just keeps coming! We learned about Pikachu's squirrel origins the other day, and now we learned that there's a lost evolution for Pikachu as well! The info comes from Pikachu illustrator Atsuko Nishida, who said at one time, there was an evolution for Pikachu after Raichu called Gorochu. The design included fangs and a pair of horns! The evolution ended up being cut from the game due to balancing issues.

from GoNintendo