The Imaginal Starship Onigashima
The benefactors are carbon-based bipeds, sharing traits with aquatic mammals and amphibians. They possess an internal skeleton with a spine, and breathe oxygen. They possess blood based on hemocyanin, which gives it a blue color, and makes them better able to tolerate low oxygen environments than humans.
All benefactors are presumed to possess psionic capabilities. It is unknown how powerful these abilities can be, as benefactors rarely demonstrate them, but it is known that most possess some form of telepathy and telekinesis.