Nestor is an alien entity who inhabits the bodies of "hundreds of thousands" of facets across the galaxy. They all share a mind, their sensations and experiences all feeding the same entity. This state is something they find exceedingly boring, as such they travel the universe seeking excitement.
Their spaceships require four facets to operate, and will always carry a fifth "spare" as well. They have virtually no tolerance to pain. They seem to have a very acute sense of taste, as they can identify the exact chemical make-up of a hot-dog while taking a bite.
- Battle Beyond the Stars (1980)