Long and sleek cetaceans, aerophins resemble Terran dolphins. They have evolved much differently than dolphins, however, and have uniquely adapted to the Epoan environment. Aerophins are amphibious mammals, living in both the water and the sky. The aerophin’s green-gray skin is marked by numerous skin flaps along the torso, flaps which can fold up and act as small sails to catch the wind and maneuver. The modified fins of a aerophin can be more than a meter long and widen near the middle, acting as wings to catch the thermal currents of the sky. The tail is muscular and the fluke parallel to the body, able to get strong thrusts in both the water and the sky. Their beaks are long and narrow, perfect for picking fish from their schools and birds from their flocks. The color of the aerophin’s skin comes from a biologically occurring form of pantarbe, allowing them to float surprisingly well for a creature of its size.
Aerophins travel in pods of anywhere from three to twenty individuals. They are quite intelligent and are skilled hunters, able to herd flocks of birds like schools of fish for easier prey. Vocalization is much like that of Terran dolphins, with a variety of clicks, squeaks, and chirps, many beyond the auditory range of humans. They have very sensitive hearing both above and below the waves, giving them the ability to hear for prey and predators. While perhaps not as agile in the sky as creatures that dwell exclusively there, many consider them to be twice as graceful as they float and "swim" in the air.
A few alchemists can distill a pure form of pantarbe from aerophin skin, thus some pods are hunted to near extinction by poachers. Quite intelligent, they have been known to fight off attacking wyvrens from vagrant cloud hoppers and wayward travellers. A few frontiersman on some of the more far flung islands of Epoa claim to have such rapport with the creatures that they’ve tamed and saddled aerophins. The legitimacy of these claims are somewhat dubious, but stranger things have happened.