The Cadassi, or "ships' friend", are space inhabiting creatures similar is structure to the Lamia and Melusine with a squid-like body with tentacles at the 'head' end and a pointed body. It is possible that these creatures are all also related to the Citali.
Much smaller than its nearest relatives the Melusine, the Cadassi mainly feed on smaller asteroid type matter, including spaceship debris, however like the Melusine they will also drift through interstellar space feeding on hydrogen and starlight.
The Cadassi need only two things to live; energy and matter. They can absorb both through their 'mouths' located at the centre of their tentacles matter particles, typically molecules of hydrogen, are syphoned off in to one storage chamber or 'stomach' and energy particles, typically photons, are stored in another stomach made of a special kind of force field. From such basic materials a Cadassi can synthesise anything it needs
They are much preyed upon by the larger and more ferocious Lamia, however they have evolved a defense mechanism. When attacked they can release the contents of their 'energy stomach' this may cause the Lamia or space shark to flee or at least confuse it long enough for the Cadassi to escape.
One of the strangest habits of the Cadassi has also given it it's common name, the ships' friend. It has a tendency to race along side ships, probably to take advantage of the wake effect they generate in hydrogen clouds, though they do seem to genuinely just enjoy it. Perhaps because of this behaviour they are seen as good luck if they follow the ship. Also some spacemen consider them to be the reincarnated souls of dead spacefarers. This superstition runs so deep that many spacemen will not travel in a ship or with a person known to have been involved in killing Cadassi. However Cadassi 'energy stomachs' are much prized as containment fields for reactors.
The Citalli are known to keep Cadassi as pets and some suspect that they farm them for the heavier elements the Citali cannot synthesise.