The Tarns are a humanoid species who developed an advanced civilization as of the 21st century. Tarns are light green skinned with three eyes, one nostril between them, and two pointy ears. Like humans they have one heart and liver, but unlike them Tarns have three kidneys. They posses telepathic and telekinetic powers, activated when the third eye on the forehead is opened. Tarns are a very sturdy species, able to survive a broken spine which would paralyze a human, and the spinal chord is able to regenerate after a while. However, Xyron Fever is extremely deadly to Tarns (Xyronites appear in 'Protect and Survive' and 'Hate Street'). They are also oviparous, being able to lay jellied see-through eggs like frogs do, and the embryos cannot survive unless the egg-sacs are in a controlled environment. A number of them worked for the Demeter City police force on the planet Altor in the Epsilon Eridani system in the year 2040.

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