Planet of origin: A planet orbiting the star Caph, in the Milky Way
The Caphians are massive humanoids with aggressive behaviours who had developped an interstellar civilisation as of the 23rd century and made contact with humanity. Despite the warlike nature of the Caphians, peaceful commercial relations were established on the basis that Caphians do not understand the concept of lying or inventing fictional concepts. Mankind started selling stories and entertainment goods to the Caphians.
Source: so bright the vision, by Clifford Donald Simak