Hi, Patrick here (the one who runs the site :P). The following article comes as a special treat to anyone who considers themselves big Nidoran family fans. Even less interested Nido fans should check this out.
This fanon Pokedex entry for all Nidos comes from the site TvTropes, but more specifically, was written by Silent Reverence, with additional help and collaboration (such as editorial work) from Crow T. Robot and Luigifan, among others. It's possibly the largest article (of any kind) I've ever seen written about Nidos, and really goes in depth where the Pokedex doesn't. Be warned though, it is a very long read.
For you impressionable types, keep in mind the contents aren't 100% canonical, but are based off of using official sources such as the games, anime, manga and trading cards with blanks being filled in from there. It also gives a more realistic suggestion of how they'd interact with each other and humans in the real world. In fact, using this as a basis, I don't think I'd ever want to own one if the opportunity presented itself, they're all way too dangerous. Overall, it's a well thought out and well organized interpretation.
Anyway, I'm happy to be able to present this great effort, which just goes to show the extent of one's imagination (and "Gushing About Characters You Like", which is why this site exists anyway :) ), and that's mostly what this site is about. So without further ado...
The Pokédex - Extended Fanon Edition: Nidoran