Nidoran♂ is a small, quadruped rodent-like Pokémon. It is pinkish purple with darker spots, and has large, spiny ears with teal insides, oversized front teeth, and red eyes. Its back is covered with three lines of large spines that can release potent poisons if threatened. The center line of spines is taller than the other two. The size of the long, pointed horn on its forehead is indicative of the strength of its venom. Nidoran♂ is an exclusively male Pokémon, Nidoran♀ being its female counterpart.
Nidoran♂ constantly listens for the sounds of approaching enemies with its large ears. Said ears have unique muscles that allow them to be moved in any direction, and even the slightest sound does not escape Nidoran♂'s notice. In order to listen to distant locations, it flaps its ears like wings. When angry, it extends its toxic spikes and charges, stabbing with its horn to inject poison. Nidoran♂ lives in open spaces, such as savannas and plains.
Nidoran was the first Pokémon to feature gender differences, and even gender; however, their difference is much greater than most later Pokémon.
Despite the addition of genders in all Pokémon starting in Generation II, the two variations of Nidoran remained separate species, rather than a singular species that splits down different evolution paths based on gender.
When an Egg is produced from Nidoran and Ditto parents, the gender ratio of the Egg favors the gender of the non-Ditto parent by an unknown margin.
A Nidoran♀ Egg has a chance of hatching into a Nidoran♂ when bred with a non-Nidoran♂ compatible father.
Due to the fact that its gender, ♂, is included in its name, checking Nidoran♂'s summary from Generation II onward will display as if it were genderless if it does not have a nickname. If its nickname is anything other than "Nidoran♂", its gender will appear as normal.
Nidoran♂ is the only Pokémon with a base stat total of 273.
Nidoran♂ may be derived from needle. It may also come from cnidocyte, a type of venomous cell responsible for the stings delivered by stinging animals, most notably jellyfish. Alternatively, it may be based on 二 ni (two) or 二度 nido (two times/two degrees) referring to the two distinct evolutionary lines with similar names and traits. Also, the Japanese word ran is translated as orchid in English. Orchids are flowers that can be purple or blue, these being the same colors as the male and female evolutionary forms of Nidoran, respectively. The ♂ is an indication of its male gender.