Giant Spiders are creatures with ten legs living on the Ruins planet. In 2009, Lt. Matthew Scott, Chloe Armstrong, Eli Wallace and MSgt. Ronald Greer encountered two of these while exploring the tunnel network on this planet. Greer shot one causing the ceiling of the tunnel to collapse, blocking their only escape route.
It is unknown how aggressive and dangerous it actually is. They are apparently web-building rather than hunting spiders, and appear to be solitary creatures, as a single spider was all the group encountered in the immediate area. (SGU: "Human") They found a second later on, but it did not attack, either. (SGU: "Lost")