Felis sapiens (designated Felix sapiens by Hudzen-10, and given the ancestor species Felis erectus in the novel Infinity Welcomes Careful Drivers) are a fictional, sentient, humanoid species in the Red Dwarf franchise. The series generally refers to them simply as Cats. They are all originally descended from a single pregnant domestic cat of Earth-origin, named Frankenstein, a pregnant pet cat of Dave Lister whom he bought on shore leave on Mimas for companionship after breaking up with Kristine Kochanski.