This mod adds a huge variety of pokemon in the game. Innovation in this fashion is very difficult to list, because there is more code than in the entire game ...
Browse and download Minecraft Pixelmon Mods by the Planet Minecraft community ... SideMod Pixelmon 3.5.1 | Minecraft 1.7.10 Minecraft Mod · SideMod Pixelmon 3.5 ...
This is like Pixelmon, just enhanced with a few mods. Note: I do not own Pixelmon, 100% credit to the author. This is just a modpack that adds some more mods.