Its auditory sense is astounding. It has a radar-like ability to understand its surrounding through slight sounds.
(From Bulbapedia) Audino is a bipedal, pink-and-cream Pokémon with oval, blue eyes. The top of its head, its back, and arms are pink, while the lower half of its face, body, ears are cream-colored, as well as its front and fingers. The patterning of pink and cream on its chest resembles a jacket. There are three digits on its hands and two on its feet. It has a puffy, white tuft for a tail. Audino has floppy ears with thin, curled extensions on the underside. It can use these ears as radars, and it has an incredible hearing ability. The feelers on its ears act like stethoscopes in that it can feel the beat of another Pokémon's heart, to assess the Pokémon's feelings and overall physical condition. The feelers are also able to determine when an Egg is close to hatching.
When Audino Mega Evolves into Mega Audino, it becomes both heavier and taller. The patterning on its stomach, now completely cream, is covered by what resembles a flared lab coat. Most of its body becomes white with pink tips in four places, one on each ear and near the edges of its "coat". Its eyes turn pink and its ears stand upright with longer, curlier feelers. Its tail becomes larger and a smaller tuft of fur is centered on its chest. Two additional, curled feelers extend from under this extra tuft of fur. White fur covers its feet with two small tufts on the heels. Mega Audino can release pulses that reduce hostility, and the secondary feelers can put those who come in contact with them into a deep sleep.
Audino is also the only known Pokémon to know Secret Power naturally by leveling up.
(From Bulbapedia) Audino seems to be partially based on rabbits, with features similar to that of a physician or nurse. The stethoscope-like feelers on its ears also bring to mind a butterfly's antennae, or proboscis, and the ears themselves resemble butterfly wings, especially in its Mega form, which may mean it was based on some depiction of a fairy. Mega Audino could take some influence from angels, as well as doctors. Mega Audino may also have a resemblance to the Sweet Lolita fashion style, having flowing, white and pink "coat", "boots" and ears.
(From Bulbapedia) Audino may be derived from audio and a pun on the phrase "I dunno." It may also refer to the suffix ino (which denotes youth) or involve din (loud noise, referring to the fact that it has stethoscopes for ears) or lapin (a term for "rabbit").