Jones, nicknamed "Jonesy", was a ginger American Shorthair tomcat kept aboard the USCSS Nostromo as Ellen Ripley's pet. While the cat's official purpose was to control rodents aboard the ship, it also served as a source of relaxation and entertainment for the crew on long space journeys.

Owing to Jones' small size and mass, he comfortably shared a hypersleep capsule with one of the crew members during the Nostromo's long journeys. When the Alien began stalking the ship's occupants, Jones was apparently of little interest to the creature and he survived the incident unscathed. However, he was indirectly responsible for the death of Brett. When the latter pursued Jones through the ship's cargo hold, seeking to catch him so that he would not be accidentally picked up on the motion trackers being used by the crew to hunt the Alien, the cat inadvertently lured him into a room where the Alien was hiding. Jones saw the Alien drag Brett's body into the air shafts. Ripley later found Jones and put him in a carry case.

Jones and Ripley were the only individuals who survived the Nostromo's encounter with a Xenomorph and the ship's subsequent destruction.

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