Wraith (Stargate)
In the science fiction television series Stargate Atlantis, the Wraith are a hive-based species that drove the Ancients out of the Pegasus galaxy long ago and is currently the main enemy of the main characters of the show.
The Wraith maintain thousands of worlds populated by humans whom they feed off of by directly draining "life force" from via organs in the palms of their hands, causing their victims to rapidly age and then mummify. The Wraith follow a cyclical feeding pattern: they lay in a dormant/hibernation stage for many years or generations, then sweep through the Pegasus galaxy to "cull their human herd", then resume hibernating when there are just enough surviving humans to maintain a breeding population for the next culling cycle.
The Wraith have pale blue skin, black eyes, and either white or red hair (in the case of the Queen Keeper seen in the pilot). They are tough to kill due to the amazing power to regenerate; emptying a P90 clip into a Wraith will stun it, but within a matter of less than 2-3 minutes it will be back on its feet. Their recuperative ability is apparently affected by how recently they have fed; The Queen Keeper in the pilot was shot while in the act of feeding and was able to heal her wounds almost instantly. They appear to have a psionic ability that can confuse their prey with false "ghosts" lurking just out of sight around them. They also have some form of collective conciousness, or at least extensive telepathic communication with each other. The Wraith are genetically related both to a species of large tick-like insect that lives on their homeworld and to humans; it is speculated that the tick-like species evolved rapidly into Wraith by assimilating human genetic material when they fed on them. The Wraith written language is similar to that of the Ancients and is apparently derived from it.
They have ships known as "Darts" which are designed to travel through the stargate, as their stargate (on at least one of their worlds), unlike most, is in orbit around their planet. Wraith hand-weapons are Stunners, designed not to kill a target, but to temporarily paralyse them for later culling. Their technology is highly advanced and rivaled that of the Ancients. The Wraith civilization appears to center around massive "Hive-ships". One was seen in the pilot episode, although because it had been laying dormant for centuries it was overgrown with trees. Intelligence recovered from a downed Dart flight-computer and a deserted Hive-ship revealed that there are over 60 Wraith Hive-ships in the Pegasus galaxy. Hive-Ships are sometimes escorted by smaller "Cruisers". Supply Ships for transporting captured humans for feeding also exist, one was discovered crashed on a desert planet located in the same star system as Atlantis.
The Atlantis expedition captured and held a Wraith prisoner for a while, until he was inadvertantly poisoned in an experiment attempting to develop a drug that could be administered to a human to prevent a Wraith from being able to feed on them. Since he would not reveal his name, Major Sheppard dubbed him "Steve."