An alien civilisation created by Vernor Vinge in his novel A Deepness in the Sky. They are about human-size creatures, and they live on the planet Arachna that orbits the OnOff star, a star that is active for tens of years, then dormant for hundreds. When it's dormant, the planet shuts down, and the Spiders must hibernate or as it is called, go into the Deep. The civilisation would rebuild itself slowly after each reemergence of their sun. Obviously, their physicall appearance is like that of spiders.

There are all sorts of social stigma about having children at a time close to the coming of the Deep. Such children are called oophases and are generally shunned, the same way that bastard children were shunned until early in the twentieth century. Young spiders called attercops (this is an interesting choice of term, it's the Old English name for a spider meaning "poison head") ride on their father's furry back.