Aria Pokoteng is indeed a cat. In ARIA, there is an earth-cat and aqua-cat. If I recall correctly, Aria shachou belongs to the later ^^ili (Info on characters can be found printed on the inner cover of JP manga)
Ah, Hime-shachou is an earth-cat ^^
Ps. Woland-san, your signature is sooo Kinoness >w<!