Sendrils are a species of 'thin atmosphere ring fauna' which lives in the ring system of the planet Soruica. They are roughly dagger-shaped, with two long, ribbon-like appendages which aid in very slight adjustments in direction and in clinging to debris orbiting within the rings. Sendrils can only propel themselves forward by expelling jets of molecular oxygen gas from two caudal vents.

The creatures are often preyed upon by Soruica ring-eels, which take advantage of the sendrils' need to detach from debris periodically to find food and their poor maneuverability. The sendrils' tendency to be easily chased out of the ring system's atmosphere also makes them a popular prey choice of the eels.