One of the most iconic characters in Nintendo's stable of diverse characters is the yellow-furred rodent, Pikachu. The part-squirrel, part-mouse looking creature with the ability to shoot out lightning actually had a very different kind of look than the one that it ended up with in the Pokemon cartoon and video games.
The Gorochu would have been a rather vicious looking creature. Interestingly enough, Gorochu didn't make the cut not because it turned Pikachu into a rather dangerous looking beast, but because there was some content culling that had to take place in order to maintain game balance back then on the old Game Boy.
You see, in the old days there were huge issues with game balance, memory load, and processing power. The old carts were extremely limited in their memory capacity, forcing developers to have to think outside and around the box in order to squeeze certain kinds of content into the cart. So, obviously, certain designs, certain features, and certain functions had to be cut from the initial Pokemon. Some of the original designers at Game Freak have often talked, in interviews, about how difficult it was to design the original game and achieve what they could while dealing with those limitations.
Nishida explains that Pikachu was originally a mixture of a mouse, squirrel, and daifuku, the latter of which is actually a Japanese pastry. The idea was to put ears on a daifuku and then evolve it from there. Nishida refined the concept until Pikachu resembled more of a mouse and squirrel fused with a daifuku. The original design was really plump and cute, but was further refined to look the way it currently does.
Interestingly enough, the other two designers had started work on the Pokemon for the first game, but many of them had what they described as "boyish" designs. This was because in the original concept of a game about capturing and battling monsters against each other, they were working on the premise that the monsters needed to look and be tough, so some of the early characters were designed to be tough, such as Snorlax, Lapras, Gyarados and Mewtwo. However, when Nishida joined she began designing more cute characters, such as Pickachu. The rest is basically history.
Interestingly, the trio of artists don't actually discuss whether or not they will ever add Gorochu to the game, but given that Game Freak is constantly evolving the Pokemon franchise with each new iteration on Nintendo's beloved hardware, maybe we'll see it make an appearance in the upcoming Nintendo Switch outing of Pokemon? I suppose we'll find out once the Pokemon Company reveals more details about the game either later this year or next year.