When it is with its friends or family, its barbs are tucked away to prevent injury. It appears to become nervous if separated from the others.
(From Bulbapedia)Nidorina is a quadruped, light-blue Pokémon with darker blue patches. It has red eyes, large, spiny ears, and has two pointed teeth protruding from its upper jaw. It possesses large poison spikes, which it retracts whenever it is with a group and while resting in its burrow. Its paws have three claws each, and it is able to stand on its hind legs. The hind legs are longer and thicker than its forelegs. It has a stubby tail. This is a female only species; the male counterpart is Nidorino.
Nidorina is a gentle Pokémon, known to be a caring mother that chews food for its young. It seems to display close family bonds with others of its kind, and becomes nervous when separated. Nidorina prefers not to fight since its horn grows slowly, but if forced or enraged, it prefers physical attacks such as clawing and biting. It also emits ultrasonic cries to befuddle foes. Nidorina lives in hot savannas and plains.
(From Bulbapedia) Nidorina appears to be based on a porcupine, rabbit, mouse or hamster.
(From Bulbapedia)Nidorina may be a combination of needle and rhinoceros. Nido may also be based on cnidocyte, a type of venomous cell responsible for the stings delivered by stinging animals, most notably by 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 using the name with similar names and traits. Rina likely alludes to its female gender; in some languages, such as Spanish and Italian, names and words ending in a are an indication to the female gender.