Jellycopters are a strange non intelligent species native to the skies of planet Koje.
Part plant, part animal, part something from a lunatic's dream; the Jellycopter actually consists of two lifeforms living in symbiosis: its body is a small jellyfish-like animal with several tentacles, some specialized for feeding on air plankton, some for grasping larger flying forms; its propeller on the other hand is a photosynthetic (plant-like) creature, rooted within a special cavity of the animal's body.
The Jellycopter uses special muscles for rotating the base of its fan-shaped symbiotic plant causing the entire structure to spin like a propeller, giving it the power of flight. Inside the cavity the jellyfish body secretes mucous substances which give the plant nutrients and also reduces friction to a great extent. With such an energy-consuming lifestyle, the Jellycopter is a relatively short-lived fellow: it only lives as long as to cross the ocean in order to spread its seeds to other continents, and then it dies.
Interestingly, sometimes if the body falls on the right place the plant propeller might remain alive and grow, consuming its dead host and becoming a large, tree-like sessile creature. But do not expect fruits from it, for the plant's offspring are also contained within the Jellycopter's seeds. The relationship between the two parts of this living helicopter is one of the greatest examples of symbiosis ever encountered on Obeidon. We can only speculate about the mechanisms that allowed this beast to evolve.