Nidorino is a light purple, quadruped Pokémon. It has several darker purple spots 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. It 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. Its short legs have three claws on each foot. This is a male only species; the female counterpart is Nidorina .
Nidoking is a large, bipedal, purple Pokémon with distinct reptilian features. It has narrow eyes, large, spiny ears, fur-like tufts on its cheeks, and a short snout filled with pointed teeth. There is a long, venomous horn on its forehead and a ridge of spines down its back. Gray plates cover its chest and belly, and there is a gray rounded spine on each elbow. Each hand was three claws, while foot has only a single hoof-like nail. It has a long, powerful tail. This is a male only species; the female counterpart is Nidoqueen .