Nidoran♂

Nidoran♂ (ニドラン♂, Nidoran♂) is one of the original 151 Pokémon in the first generation. Prior to the introduction of genders in the Pokémon video games, this Pokémon, its evolutions, and the Nidoran♀ evolutionary family were the only Pokémon whose genders were made explicit. Male Nidoran have larger horns than the females.

The name Nidoran♂ follows the same conventions as those of the other Pokémon in the Nidoran family. Nido (二度, Nido) is the Japanese word for "two times" or "two degrees," which is indicative of the differences in the genders of the species. Nīdoru (ニードル, Nīdoru?) is also the Japanized pronunciation of "needle", which Nidoran are covered in. "Ran" may derive from pacarana, a South American type of rodent. It evolves into a Nidorino then into a Nidoking.

Characteristics
Nidoran♂ has a well-developed sense of hearing due to its large ears. Nidoran♂ can raise its ears to check surroundings, after which it would move them in many directions to detect danger. Like the female, the male Nidoran looks like a rat, only it has a horn since birth.

Before the concept of Pokémon gender was introduced in Gold and Silver, Nidoran♀, Nidoran♂, and their evolutions were the only Pokémon that were identified by gender. The Nidoran are the only Pokémon prior to the release of Pokémon Diamond and Pearl to have gender-specific evolutions; for the purposes of the games, however, the two genders have always been treated as distinct species with separate Pokédex entries for both themselves and their evolved forms.

A Shiny Nidoran♂, and all of its evolutions are blue, to show colors of the opposite gender.

Appearance
Nidoran♂ first appears in Pokémon Red and Blue, alongside its female counterpart, Nidoran♀. He eventually evolves into Nidorino. Before genders were introduced for most Pokémon, Nidoran♂ and Nidoran♀ (and its evolutions) were the only Pokémon with a gender.

Nidoran♂ is common in Fire Red but Rare in Leaf Green. He is found on Route 3 and in the Safari Zone Areas 1, 2 & 3.

Anime
Nidoran♂ appears in an episode alongside its female counterpart, where the two Pokémon fall in love, and Ash and Misty try and get their Trainers, Ralph and Emily, who have been rivals all their lives, together, too, especially if Ralph and Emily were going to rescue their Nidorans from Team Rocket. In the American version of the episode, the two Nidorans were named Tony and Maria, the names of the leads from West Side Story. After the battle with Team Rocket, and after kissing Emily's Nidoran♀, Ralph's Nidoran♂ evolved into Nidorino.

Manga
Shū caught a Nidoran♂ in Pokémon Getto Da Ze!. A battle between a Nidoran♂ and Clefairy was how Isamu Akai met his Clefairy in Pocket Monsters.

Trading card game
Nidoran♂ has appeared in the Pokémon Trading Card Game in the Base set series, Gym challenge series as Giovanni’s Nidoran♂, EX Fire Red & Leaf green, Base set 2, and Legendary Collection.