Sa'Vasku (SV) alien bioships
The Sa'vasku have been around for a long time, and have seen many younger starfaring civilisations rise, falter and die over the millennia. The Sa'Vasku themselves are huge, almost immobile creatures that live a semi-aquatic xistence surrounded and tended by their myriad biotech constructs; they are not immortal, but are incredibly long-lived by human standards, with lifespans into thousands of years. There are only a small number of actual Sa'Vasku on each of the worlds that form their domain, and they seldom leave those worlds, carrying out almost all contact between their own worlds and with other races by proxy through their constructs.