Medusan emblem.
The Medusans are a race of intelligent non-humanoids native to the planet Visalayan in the Xi Hydrae star system, whose outward appearance will drive a Human insane if they look at one directly without a protective visor. (TOS video game: Star Trek: Starfleet Academy - Strategic Command) This current appearance/form of the species was achieved 600 thousand years earlier. (ST module: All Our Yesterdays)
They were noted as a race of highly intelligent nonphysical beings that were composed of electromagnetic energy. The Medusans demonstrated highly advanced scientific capabilities and had telepathic powers that were more advanced than anything other race within the United Federation of Planets. Should it be necessary, a Medusan was capable of travelling onboard a Federation starship though this required them to be within highly specialized electromagnetic containers. There was a great deal of danger in such cases as whilst their mental thoughts were sublime, their physical appearance was so hideous to humanoid eyes that they drove a subject insane. Special viewers were required by individuals who sought to see a Medusan outside their protective containers as they filtered out the dangerous frequencies from the eye lids thus lessening the potential damage.
The Medusans were noted as expert starship navigators and had developed interstellar navigation into a fine art which was attributed to their unique sensory system. One theory suggested that the race were capable of electromagnetically identifying as well as locking onto guide stars, even those that were beyond deep sensor range. They were noted as having a distinct form of beauty and were delighted by the many forms of art available to them since their entry into the Federation. (ST reference: The Worlds of the Federation)
Contact between them and the Federation was extremely limited. (ST reference: The Worlds of the Federation) Medusan starships were known to be equipped with specialist feeding chambers. (TOS novel: Spectre)
