List of fictional alien species: R From Wikipedia the free encyclopedia List of fictional alien species A B C D E F G H I J K L M N O P Q R S T U V W X Y Z Name Source Type Raas Master of Orion III Rabotevs Harry Turtledove's Worldwar book series A subject species of the Race in the Worldwar book series The Race Moreau series Amoeboid The Race Harry Turtledove's Worldwar book series Reptilian, often called "Lizards" by humans due to their appearance. Rachni Mass Effect Radicles OK K.O.! Let's Be Heroes Raiel Peter F. Hamilton's Pandora's Star Rako-Gorda Utopia Ram Pythons Battlelords of the 23rd Century Rancors Star Wars Raptors Nexus: The Jupiter Incident Raxacoricofallapatorians Doctor Who Reapers Doctor Who Reapers Mass Effect Reapers X-COM: UFO Defense Regul C. J. Cherryh's Alliance-Union universe Relgarians Farscape Humanoid Remans Star Trek Humanoid Re'ol Stargate SG-1 Humanoid Replicators Stargate SG-1 Artificial lifeform. Two variants are known to exist, in a small mechanical insect shape as well as full humanoid. Re'tu Stargate SG-1 Rigellians Lensman books Barrel-shaped with four tentacular arms and four stubby legs Rigellians (including Kang and Kodos) The Simpsons Riim The Voyage of the Space Beagle by A. E. van Vogt Rills Doctor Who Rimerunner Expedition Rimmer Red Dwarf Hologram-humanoid Risians Star Trek Risians are extremely open and will freely share their planet, and even themselves, with vacationers – a practice known as "Jamaharon". Robotech Masters Robotech Rodians Star Wars Roger the Alien American Dad! Rogue Simulants Red Dwarf Humanoid Romulans Star Trek Humanoid Rull The War against the Rull by A. E. van Vogt Rutans Doctor Who Ryouko Asakura The Melancholy of Haruhi Suzumiya Humanoid interface Ryqril Timothy Zahn's The Blackcollar