If one were to pick two words to describe the being before you, the best two may well be 'acid trip'. The basic shape is that of an anthropomorphic fox. However, the color, or rather colorS, are striking. Every color of the rainbow, and then a few, reflect off his body in a kaleidoscopic miasma of light and random patterns as he moves. The slightest gesture causes his colors to shift and swirl like an oil slick atop a water puddle. The only part of his body that retains a single color is his tail ... or more accurately, his tails. He possesses seven of them, each a different color of the rainbow. The tailtip, traditionally white on foxes, is instead simply a lighter tint of the main tail's color pink on the red tail, etc). The puffy tails swish and sway constantly, wrapping around his leg or any nearby objects as if they had minds of their own. Every move he makes generates a sound to accompany the lightshow; the pitch and volume differ, but the sound is most definitely a squeak, the sound of rubber sliding over rubber. The sheen and sleekness of the fox's skin are nearly identical to that of a toy balloon, which he appears to resemble in construction. He maintains his modesty through the use of a pair of simple jet-black shorts that extend to his knees.
Air is one option, but there must be others.
Chocolate Syrup: Acts like a mild 'upper'. Rinzen doesn't quite get high, but it makes him more pleasant... and hungry.
Breastmilk: Acts as a mild aphrodesiac, makes Rinzen more 'feminine' sexually, and seems downright eager to leave her body via tits or cock. (Relevant log: Right here.)
Helium: A simple aphrodesiac, which, given how horny Rinzen USUALLY is, can be quite dramatic...
Ditzium Gas (TM): Reduces (or enhances) Rinzen to a ditzy bimbo, composed of helium and a sugar vapor.