Source: The Thrushmoor Terror, pg(s). 90–91
Star vampires are naturally invisible until feeding on blood, which infuses their bodies with a glistening crimson hue. A star vampire's central toothy maw is surrounded by tangled masses of writhing feelers, and it can extend three long talon-tipped tentacles to lacerate foes, allowing them to drink blood from the air with thousands of tiny feeding tendrils. A star vampire is approximately 10 feet in diameter and weighs 300 pounds, though some can grow bigger and mightier.
The star vampires are ancient beyond most worlds and have forgotten entirely about those who first spawned them, or any culture or name they might have once had.
The bulk of star vampires drift through the Dark Tapestry, and each can spend up to millions of years before finding a planet upon which it can feed. Once a star vampire adopts a feeding ground, it very rarely, if ever, returns to space.
Star vampires are more commonly found on worlds after being summoned by rare spells or rituals, which are deliberately ambiguous promises of the aid of a powerful spirit from the depths of space, designed to turn the unsuspecting caster into the star vampire's appetiser. These spells were likely devised by a misanthropic lunatic eager to bring pain and doom upon those foolish enough to attempt to contact aliens.
Star vampires emit strange noises that seem to serve no purpose, although they sound like mocking laughter at times. They can speak, but their voices are wet, slobbery and mixed with the tittering noises, which are only silenced when the star vampire feeds.
Star vampires have no need for companionship, a legacy, or the colonisation of new worlds. Some star vampires develop human goals and desires beyond simply feeding, becoming oracles, psychics or rogues. They are fond of forming cults and playing god to primitive societies or fanatics who know no better. Star vampires are usually atheists; those that are not tend to follow Nyarlathotep, Shub-Niggurath, or Yog-Sothoth.