The Ripley

The Ripley (also known in the novel as "byrus") are a fictional complex parasitoid alien macro virus that appears in the Stephen King novel "Dreamcatcher" (as well as the film based on the novel).

The adult aliens resemble deformed potato beings with legs, while the younger aliens - nicknamed "shit-weasels" because they can be created in a host organism's stomach and escape by eating their host's body between the stomach and anus - are legless, smaller versions of the adult alien. Both the adult and young aliens have a mouth that consists of a slit on the underside of the head that goes down the length of the worm. The mouth lips separate to reveal hundreds of teeth that can bite through steel.

Their name is a reference to Ellen Ripley, the fictional main character in the Aliens series of films, because in all stages the parasites are extremely difficult to destroy, and as said by General Kurtz, "This disease is one tough mother to beat, just like that alien chick."

Both the adult and "shit-weasel" aliens are capable of immediate asexual reproduction using eggs. The eggs hatch into even smaller versions of the "shit-weasels" that already have the carnivorous instinct of the adult aliens.

The adult aliens are capable of not only telepathy, but the ability to give those around them telepathic abilities. They can also manipulate the minds of those around them. They use this power to appear as "Gray Boys". "Gray Boys" look nearly identical to the stereotypical grey alien look (it is mentioned in the story that the Ripley have been plaguing Earth since 1947, the year of the Roswell crash), but with pus-like skin. "Gray Boys" may spontaneously explode in a cloud of red dust for two reasons: if near death, or as one final attempt to spread the infection.

In the story, an adult alien appears behind the character Jonesy as a "Gray Boy" and promptly explodes to infect him. However, because of his special telepathic powers, Jonesy is instead taken over by this particular Ripley, named Mr. Gray, so it can escape in his body and embark on a mission to infect the rest of the world.

The virus itself is able to rapidly manifest itself and infects any living host on contact. Half of the infected people are able to recover, while the other half usually die from the parasites that grow inside them. The virus takes on the form of a rapidly growing redish-gold moss.

A minor note is that the "Gray Boys" and "shit-weasels" are not the same beings in the book. The "Gray Boys" are the image we see the aliens as while the "shit-weasels" are a different alien that coexists with the "Gray Boys" and is spawned by an abundance of byrus. The "shit-weasels" give the "Gray Boys" their telepathic ability, but since they are created from the byrus, the byrus can also give one telepathic abilities.

Weaknesses and Strengths

The "shit weasels" are stronger than humans, both in the ability to withstand pain and in physical strength. However, they die from almost anything that would kill a human. They are especially frail in the cold, thus it can be assumed that they originate from a warmer planet.

The aliens are covered with a mucous-like substance to withstand their hosts' stomach conditions. The mucous quickly becomes viral on surfaces.