Nidorino is a light-purple, quadrupedal mammalian Pokémon. It has several darker purple patches across its body. It has large, spiny ears with teal insides, narrow black eyes, and a long snout with two pointed teeth protruding from the upper jaw. Nidorino has a ridge of toxic spines on its back and a long pointed horn on its forehead. The horn is harder than a diamond and capable of secreting poison on impact. The more adrenaline Nidorino has in its body, the more potent the poison is. Its short legs have three claws on each foot. Nidorino is a male-only species.
Nidorino is independent, nervous, and fierce, and it is often described as violent and easily angered. It uses its ears to check its surroundings. If it senses a hostile presence, all the barbs on its back bristle up at once, and it challenges the foe with all its might. Nidorino's harder-than-diamond horn can destroy diamonds, and it uses that horn to destroy boulders in its search for Moon Stones. Nidorino live in hot savannas and plains.
In Pokémon - I Choose You!, a Nidorino was going up against a Gengar in a battle that Ash was watching on TV. Thus, Nidorino and Gengar were the very first Pokémon to be seen in the anime, excluding the intro.
In Fire and Ice, Ash battled a Nidorino during the Indigo Plateau Conference. He reappeared in a flashback in Friends to the End.
In Wherefore Art Thou, Pokémon?, Ralph's Nidorino, nicknamed Tony, evolved from Nidoran♂ after battling Team Rocket and kissing Emily's Nidoran♀, nicknamed Maria.
In The Heartbreak of Brock, Temacu's Nidorino was taking a stroll with her Nidorina.
In Restore and Renew!, Jessie pulled a Nidorino from the Rocket Prize Master and used him in an unsuccessful attempt to capture a recently-revived Aerodactyl.
In The Flame Pokémon-athon!, multiple Nidorino were at the Laramie Ranch.
Two Nidorino appeared in the banned episode EP035, with one appearing in a flashback.
In A Chansey Operation, an injured Nidorino was brought to the clinic.
A Nidorino appeared in The Breeding Center Secret.
In Mewtwo Strikes Back, a Trainer's Nidorino was defeated by Mewtwo while it was serving Giovanni.
In The Power of One, a Nidorino sensed the disturbance caused by Lawrence III.
In A Tent Situation, a Nidorino was at Professor Oak's Laboratory.
In Tricks of the Trade, a Nidorino was at the Pokémon Swap Meet in Palmpona.
Two Nidorino appeared in The Legend of Thunder!.
Multiple Nidorino appeared in the opening sequence of Destiny Deoxys.
A Nidorino appeared in Pokémon Ranger and the Kidnapped Riolu! Part 1 and Part 2.
A Nidorino appeared in Arceus and the Jewel of Life.
A Nidorino appeared in the opening sequence of Zoroark: Master of Illusions.
A Nidorino appeared in Mewtwo's flashback in Genesect and the Legend Awakened.
In Mewtwo Strikes Back—Evolution, a Trainer's Nidorino was at Old Shore Wharf.
||Nidorino, the Poison Pin Pokémon. The evolved form of the male Nidoran. Its highly developed horn is extremely powerful.
In File 1: Red, a Nidorino was seen in Professor Oak's introduction, while another was seen battling a Gengar.
In the game intro-like opening sequence for The Adventure, a Nidorino was battling a Gengar.
A Nidorino appeared in A Budding Dream, having evolved from Tsubomi's Nidoran♂.
- Nidorino is one of the first two Pokémon to appear in a Pokémon battle both in the anime and in the games, the other being Gengar. This is due to their appearance in the opening animation of Pokémon Red and Green, on which the beginning of the first anime episode was based on, as well as the remakes.
- It is also the first Pokémon to be both seen and captured in Pokémon Adventures, in much the same way.
- Nidorino, along with Gengar (and, possibly, other Pokémon), originate from the old manga, Capsule Monsters, which is considered the ancestor to the Pokémon franchise.
- The Nidorino that appears in Professor Oak's introduction in Pokémon Red and Blue has the cry of a Nidorina.
- Nidorino's Shiny coloration is the same as Nidorina's normal coloration. Likewise, Nidorina's Shiny coloration matches Nidorino's normal coloration.
- Nidorino shares its category with Nidoran♂, Nidoran♀, Nidorina, Poipole, and Naganadel. They are all known as the Poison Pin Pokémon.
Nidorino appears to be based on a rhinoceros, porcupine, rabbit, mouse, or even a hamster, as seen by their aggressive and independent nature. Anatomically, however, they resebmble hyraxes – rodent-like mammals that are genetically more closely related to much larger mammals like elephants and manatees featuring thickset bodies with tough hides (similar to Nidoking).
Nidorino may be a combination of needle, rhinoceros, and -ino (masculine diminutive suffix in Spanish and Italian). It may also involve 二度 nido (twice).