Nidoran’s a bit of an odd Pokémon. With as many as their are now, I could be wrong, but I think they’re the only Pokémon with separate Pokédex entries for their males and females. They didn’t really know how to handle things like gender or breeding in the early days, so instead of just having males and females that look different we have two unique evolution lines. I did a Nidoqueen for the female side a while back, but now here’s a male Nidoran.