Aeroceta

The largest animals to inhabit Odin’s skies, Aeroceta species have developed a system of elastic organs that fill with light gasses from their digestive processes, making them buoyant and allowing such relatively heavy creatures to sustain flight.  While most of the lift is provided by these sacks, they achieve propulsion by undulating wing-like flaps on the outer edges of their stiffened arms (the claws on the inner edge used to link with other individuals during mating). Many have adapted to glide over the sea, plucking swimming Odifauna from the water with extended, tusk-like mandibles; others are less specific predators, hunting opportunistically around Understory webs.  But the largest (some growing up to 12 meters long) fly through the Upper Cloud Layer, sieving the abundant aeroplankton with highly specialized, baleen-like mouthparts.