Alpha-sapphire: Nidoran♀ has barbs that secrete a powerful poison. They are thought to have developed as protection for this small-bodied Pokémon. When enraged, it releases a horrible toxin from its horn.Y: Small and very docile, it protects itself with its small, poisonous horn when attacked.X: Although small, its venomous barbs render this Pokémon dangerous. The female has smaller horns.
Prof. Lotus' Notes: The name is a portmanteau of the Japanese borrowed word for Needle - ニドル (Nedoru), cnidocyte (thing in all poisonous animals) and rhino. Finally, 二度 or Nido in Japanese can be translated to 'two times' and this is often attributed to the Nidoran line splitting into male and female.
Gender Differences: Female is light blue and male is purple
Separate evolutionary lines