The Gasbag are a species of jellyfish-like aliens native to the skies of Jupiter. They are members of the Intergalactic Council.
They are highly intelligent, and live in small communities. Generally, they are unskilled. They communicate with bio-luminescence and color change.
They develop from a small bubble larva, to a floating polyp. The full-sized adults are 20-50 feet wide (~ 6 to 15 meters), and up to 50 feet tall (including tentacles).
- Alienology: The Complete Guide to Extraterrestrials, by Allen Gray (2010)