The cat ear plant is an unusual life form that is both beautiful and musical, and has the characteristics of both plant and animal. It has cup shaped leaves that resemble cat's ears growing all over the stems. Inside the base of each leaf a small flower forms, giving the appearance of whiskers emerging from the leaf. When wind blows across a stem covered in these specialized leaves, they reflect the waves of sound and form a musical note. Since the leaves vary in size, each tree sounds like a small symphony in the wind.
Besides its musical abilities, this “planimal” has the uncanny ability to turn in the direction of an animal, and track it as it moves through the rainforest. This can be disconcerting to humans on Pandora, who feel like they are being "watched" as the planimal turns in response to their presence.
It was the behavior of the cat ear that led xenobotanists to discover these odd creatures who straddle the evolutionary fence between plant and animal.
The leaves are collected by the Na'vi for use as musical instruments (for hufwe or "wind instruments") and children's toys. Leaves of varied sizes can be attached to a base and then tapped with a stick or blown across, which causes air inside to vibrate and generate musical notes. Water added to a leaf reduces the volume of air and changes the note, much like musical bottles played on Earth.